So this is definitely not a bug on our side, we don't deal with graphics that deeply into the system.
Because I don't know what exactly resolved the issue for you the last time, I can just guide you into the right direction.
TripleA is written in java, so any solution for another java program could potentially work.
I googled for "" and found flags like -Dsun.java2d.noddraw=true which seem to resolve some issues for some people.
(Source for reference)
Once you found your flags, you paste them into the TripleA.vmoptions file, one flag per line, save it and try it out.
This file is located inside the folder you installed triplea to.