Circle diagram made with tkz-euclide renders differently in TeX Live 2018 versus TeX Live 2020

I have another question similar to my last question about 2018 -> 2020 tkz-euclide compatibility changes.

I have a circle diagram that compiles and renders perfectly in Overleaf (TeX Live 2018):

Here is the code that compiles successfully:

documentclass[addpoints]{exam}
printanswers
usepackage{gensymb} %for degree symbol
usepackage{pgf,tikz}
usetikzlibrary{angles,arrows.meta,automata,backgrounds,calc,decorations.markings,decorations.pathreplacing,intersections,patterns,positioning,quotes}
usetikzlibrary{shapes} %For polygon nodes, see http://www.texample.net/tikz/examples/node-shapes/
usepgflibrary{shapes.geometric}

%Needed to resolve conflict between tkz-euclide and thmtools, see https://tex.stackexchange.com/questions/456029/thmtools-and-tkz-euclide-conflict
usepackage{tkz-euclide}
usetkzobj{all}
%usepackage{thmtools}
usepackage{etoolbox}
makeatletter
%%% patch tkz-tools-base.tex
lettkz@g@xatkz@init@xmin % don't undef @xa or thmtools will be upset
lettkz@g@xbtkz@init@xmaxundef@xb
lettkz@g@yatkz@init@yminundef@ya
lettkz@g@ybtkz@init@ymaxundef@yb
patchcmd{tkz@Init}
 {globallet@xatkz@init@xmin
  globallet@xbtkz@init@xmax
  globallet@yatkz@init@ymin
  globallet@ybtkz@init@ymax}
 {globallettkz@g@xatkz@init@xmin
  globallettkz@g@xbtkz@init@xmax
  globallettkz@g@yatkz@init@ymin
  globallettkz@g@ybtkz@init@ymax}
 {}{}
patchcmd{tkz@Grid}
 {(@xa,@ya)(@xb,@yb)}
 {(tkz@g@xa,tkz@g@ya)(tkz@g@xb,tkz@g@yb)}
 {}{}
makeatother
newtheorem{thm}{Theorem}

title{MWE}
begin{document}
begin{questions}
question
begin{parts}

part Find:
%from https://latex.org/forum/viewtopic.php?t=23290
begin{center}
begin{tikzpicture}
tkzDefPoint[label=above:O](0:0){O}
tkzDefPoint[label=below left:A](230:2){A}
tkzDefPoint[label=below right:B](310:2){B}
tkzDefPoint[label=above:C](90:2){C}
tkzDrawPoints[fill=black,size=10](O,A,B,C)
tkzDrawCircle(O,A)
tkzDrawPolygon(C,A,O,B)
tkzMarkAngle[size=0.75](A,O,B)
tkzLabelAngle[pos=0.5,font=small](A,O,B){80degree}
tkzMarkAngle[size=0.75](A,C,B)
tkzLabelAngle[pos=0.5,font=small](A,C,B){$alpha$}
end{tikzpicture}
end{center}
vspace*{stretch{1}}

part Evaluate the unknown arc and angle measures.
begin{center}
begin{tikzpicture}[scale=2] %from https://latex.org/forum/viewtopic.php?t=21949
tkzDefPoint (0,0){O}
tkzDefPoint (2,0){P}
tkzDefPoint (1,0){C}
tkzLabelPoint[left](O){$O$}
tkzLabelPoint[right](P){$P$}
tkzLabelPoint[right](C){$C$}
tkzDrawCircle[R](O,1cm)
tkzTangent[from with R=P](O,1cm) tkzGetPoints{T1}{T2}
tkzDrawLines[add=0 and 0](O,T1 O,T2 O,P)
tkzDrawLines[add=0 and 0.5](P,T1 P,T2)
tkzLabelPoint[above](T1){$A$}
tkzLabelPoint[below](T2){$B$}
tkzDrawArc[R with nodes,](P,0.5)(T1,T2)
%draw (T1) node[above right] {$P(alpha)=(a,cosalpha,a,sinalpha)$};
%draw (T2) node[below right] {$Q(alpha)=(a,cosbeta,a,sinbeta)$};
draw (P) +(165:0.6) node {$25degree$};
%draw (P) +(195:0.6) node {$25degree$};
tkzLabelSegment[above right](O,A){$6$ cm}
end{tikzpicture}
end{center}
vspace*{stretch{1}}
end{parts}
end{questions}
end{document}

However if you change the TeX Live distribution from 2018 to 2020, it renders differently and Overleaf spits some errors:

I learned from this thread that usetkzobj{all} shouldn’t be used with recent tkz-euclide. Commenting this line in the 2020 distribution fixes some but not all issues.

Some (undesired changes):

1. In 1st diagram, geometric points are very large
2. In 1st diagram, angles have a "tick mark" in them
3. In 2nd diagram, tangent lines to circle disappeared

Any ideas how to fix these issues? Thank you!

documentclass[addpoints]{exam}
printanswers
usepackage{gensymb} %for degree symbol
usepackage{pgf,tikz}
usetikzlibrary{angles,arrows.meta,automata,backgrounds,calc,decorations.markings,decorations.pathreplacing,intersections,patterns,positioning,quotes}
usetikzlibrary{shapes} %For polygon nodes, see http://www.texample.net/tikz/examples/node-shapes/
usepgflibrary{shapes.geometric}

%Needed to resolve conflict between tkz-euclide and thmtools, see https://tex.stackexchange.com/questions/456029/thmtools-and-tkz-euclide-conflict
usepackage{tkz-euclide}
tikzset{/tkzmkangle/mark=none}  % https://tex.stackexchange.com/a/544732
%usetkzobj{all} % <-- don't use this with the new version
%usepackage{thmtools}
usepackage{etoolbox}
makeatletter
%%% patch tkz-tools-base.tex
lettkz@g@xatkz@init@xmin % don't undef @xa or thmtools will be upset
lettkz@g@xbtkz@init@xmaxundef@xb
lettkz@g@yatkz@init@yminundef@ya
lettkz@g@ybtkz@init@ymaxundef@yb
patchcmd{tkz@Init}
 {globallet@xatkz@init@xmin
  globallet@xbtkz@init@xmax
  globallet@yatkz@init@ymin
  globallet@ybtkz@init@ymax}
 {globallettkz@g@xatkz@init@xmin
  globallettkz@g@xbtkz@init@xmax
  globallettkz@g@yatkz@init@ymin
  globallettkz@g@ybtkz@init@ymax}
 {}{}
patchcmd{tkz@Grid}
 {(@xa,@ya)(@xb,@yb)}
 {(tkz@g@xa,tkz@g@ya)(tkz@g@xb,tkz@g@yb)}
 {}{}
makeatother
newtheorem{thm}{Theorem}

title{MWE}
begin{document}
begin{questions}
question
begin{parts}

part Find:
%from https://latex.org/forum/viewtopic.php?t=23290
begin{center}
begin{tikzpicture}
tkzDefPoint[label=above:O](0:0){O}
tkzDefPoint[label=below left:A](230:2){A}
tkzDefPoint[label=below right:B](310:2){B}
tkzDefPoint[label=above:C](90:2){C}
tkzDrawPoints[fill=black,size=5](O,A,B,C)
tkzDrawCircle(O,A)
tkzDrawPolygon(C,A,O,B)
tkzMarkAngle[size=0.75](A,O,B)
tkzLabelAngle[pos=0.5,font=small](A,O,B){80degree}
tkzMarkAngle[size=0.75](A,C,B)
tkzLabelAngle[pos=0.5,font=small](A,C,B){$alpha$}
end{tikzpicture}
end{center}
vspace*{stretch{1}}

part Evaluate the unknown arc and angle measures.
begin{center}
begin{tikzpicture}[scale=2] %from https://latex.org/forum/viewtopic.php?t=21949
tkzDefPoint (0,0){O}
tkzDefPoint (2,0){P}
tkzDefPoint (1,0){C}
tkzLabelPoint[left](O){$O$}
tkzLabelPoint[right](P){$P$}
tkzLabelPoint[right](C){$C$}
tkzDrawCircle[R](O,1cm)
tkzDefTangent[from with R=P](O,1cm) tkzGetPoints{T1}{T2}
tkzDrawLines[add=0 and 0](O,T1 O,T2 O,P)
tkzDrawLines[add=0 and 0.5](P,T1 P,T2)
tkzLabelPoint[above](T1){$A$}
tkzLabelPoint[below](T2){$B$}
tkzDrawArc[R with nodes,](P,0.5)(T1,T2)
%draw (T1) node[above right] {$P(alpha)=(a,cosalpha,a,sinalpha)$};
%draw (T2) node[below right] {$Q(alpha)=(a,cosbeta,a,sinbeta)$};
draw (P) +(165:0.6) node {$25degree$};
%draw (P) +(195:0.6) node {$25degree$};
tkzLabelSegment[above right](O,A){$6$ cm}
end{tikzpicture}
end{center}
vspace*{stretch{1}}
end{parts}
end{questions}
end{document}