Focus check not working on Fuji X-T3

[AdriLo]

Hi! I recently bought a second hand X-T3 and for some reason the focus check is not working (on any lens but the 16 f1.4). I do own another X-T3 and have used the same backup with the same settings, but for some reason in the new one it doesn't want to work. Has anyone experience something similar? It's pretty annoying cause I shoot a lot with manual lenses and it a must-have feature for me.

Thanks a lot