I can not install many snaps from snapstore in gnomesoftware

I am trying to install gnome software, opentoonz and other snap from gnome software from the snap store page and he gave me these errors.!
Is this normal?

The one thing in common for these two packages you’ve mentioned is that they don’t have any releases published on the stable channel. It seems to work okay for me and install from the next best channel though.

What version of gnome-software are you running?

It seems that in some stable versions the same thing happens, look: