blender ui doesnt update as it should

i have the problem that my viewport updates only if i cklick something,
for drop-down and hover menus this is really a problem. my workaround is
to enable screencast keys, if enabled, no “lag” occurs, everything works.

i searched alot, but i didnt find a good solution for this.

i read somewhere thats some graphiccard issue and that it is a workaround, to activate screencast keys. they are not supported anymore.

so my question is: does someone has the same problem and maybe a solution?

if screencast keys runs a “update” method, is it possible, to write some small python “addon”, that is always on and does nothing else that updating… ?
i have no python experience, so i really dont know how to…

i have a geforce gt 540m with new drivers, if this information helps somehow…

cheers and thx in advance