Can't downgrade to java 8 on MineOS running on proxmox

I have MineOS running on a Proxmox vm, I tryed to downgrade Java from 16 to 8 using differents methods (also trying using the official Java guide) but nothing. I have the Java 8 folder in / opt and i’ve also created a new link in usr /bin but when i lounch Java -version it always respond me:

root @ mineos-tkldev ~ # java -version
-bash: / usr / bin / java: No such file or directory

I’ve seen that for a lot people worked, have any ideas? Thank you

Type which java then ls -la $(which java) and what does it report? Does the file it references exist, or is it a broken symlink?

It exist and it link to the right folder
this is what the -bash says:
java → /opt/jre1.8.0_301/bin/
The symlink I’ve created with ln …