@mitu
Yes I read the gpu setting on the pi4 is managed dynamically and is best left alone as it can harm performance increasing it.
I do try to keep everything default and use the advice in the documents.
I have been able to replicate the issue over and over. I decided to try turning off and on many different features under emulationstation settings and keep testing.
It's probally nothing to do with the issue but after turning OMX on and doing the test again so far ive managed to add hundreds of games without issue. I will create more collections and try again this has been the most successful for me so far. I can't really see why this would help as when adding games to the collections i don't give it time to start playing any video.
Update
Tested again with same setting OMX on with existing and new collections and worked fine.
Thanks Sim