iATKOS | United Kingdom

I have a macbook A1342 6.1, 2,26GHZ C2D. I’ve installed Big Sur with OpenCore legacy patcher. NOT SURE IF THIS HAPPENED BEFORE OR NOT. I got it basically free and it was a timecapsule from 2011, with 10.6.8 and everything from 2011(kept that hdd) Ive used it a bit on 10.6 to make sure its alright, then i just put the SSD in it. The ram is 4GB of 1066mhz ram. Although it is not new, so I would love to know if I can somehow test it. It works well apart from 2 issues. One is that on every boot i get the choice where to boot from, insteadof automatically booting into MacOS 2nd issue is bigger. If i let it idle for some hours, beit in sleepmode or just open on some app, after some time i will find it completely frozen and in need of restart. If i am constantly working on it.. movie, excel, whatever it is, it works perfectly. Only happens when left idle. I am thinking this could be RAM-Related? Are there any apps that help me check the health of RAM modules? The storage in it is a new SSD. Also overheating is not an issue. Everything works with new thermal paste applied. Thanks in advance!