Flanker maintenance issues

I’ve been reading a few things off the aicg site and I’m interested if others here have more information on the following that I’ve heard:

Venezuelan Su-30s were not new built but were part of a batch built for China and are suffering from corrosion issues partly due to that they are older, and partly due to Venezuela’s climate.

Similarly Vietnam is having issues with its Flanker availability due to spares and corrosion.

India with integration issues and spare tire issues

and Indonesia, not with availability but rather, its capabilities are still limited and isnt cleared for to use many weapons yet.