Screenshot for clarity:
I used union join to smoothen the way the different parts were joined (neck to head, head to muzzle, etc. etc.) and these squares appeared. I was following a YT tutorial and it had those too so I ignored it. Now I came to sculpt the mouth, however no matter what I do I cannot sculpt anything in the head; not the muzzle, not the horn, nothing. The only thing I am able to sculpt is the torso (I joined the wings to the torso using Ctrl+J) and I sculpted the wings and it worked so I dont' know.
The issue could be something other than union join, who knows. I have shade smooth turned on. How can I sculpt? Is there a way to fix this?
Thank you!