Macbook pro freezing and crashing randomly multiple times a day

Hi, my 2014 15” MacBook pro has been freezing and crashing at random times. I

haven’t been able to establish a pattern of behaviour to find the source of the issue. I have wiped everything and reinstalled Big Sur twice and the problem is still there. Have reset SMC and PRAM etc with no success. After some research it seems that Spotlight reindexing is causing the issue but I can't confirm . I have stopped the indexing and restarted and it is still happening... Have gone to Apple store to get it checked and there are no hardware issues...Desperate for a solution...