Fetch errors and bad retention policy after upgrade from 9.1.4 o 10.3.3

After updating from 9.1.4 to 10.3.3, many of my panels show fetch errors, or bad retention policy, etc.

I downgrades to 10.1.6 and it seems everything is working.

I tried to find the origin of the problems, but no luck, may be there are some major changes that create this trouble. Anyone has any hints?

Tks!