But why would I change the enclosure? It should work. It doesn't make sense buying an external HDD to change its enclosure because it isn't working right and to waste extra money. Besides, I don't have this problem when connecting it to the PC, only to the PS4/PS5.
I thought 5TB external HDDs always required external power supply and were always 3.5". Anyway, 5TB isn't 8TB.
Is it 2.5" and 8TB and doesn't require external power source?
There are 5TB 2.5 size HDD, 2.5 Size drive doesn't require external power, in your case it is probably good idea to actually show us what drive and enclosure you are using. If you bought the drive and enclosure separately you can try a different enclosure, if it was bundled together when you got it, some drive can be shuck