ubuntu 21.4 desktop iso burned to dvd fails to start

The ubuntu-21.04-desktop-amd64.iso burned to a dvd fails to start live session giving a bunch of error messages like:

Failed to start Snap Daemon
Failed unmounting cdrom
Failed to start Holds Snappy daemon refresh
Failed to start Ubuntu live cd installer. failed at package install time...

And then it stops. It is not a problem of corruption of the downloaded iso: I have checked sha256 and it is correct, and the if I burn the same iso with Rufus on an usb stick the live session starts without problems. It is not a problem of the dvd burner or of the dvd disc, because I have successfully burned other iso images of several different distributions (Mint, Manjaro, Mx Linux) using the same burner and dvd without having issues trying them on the same pc's.

I tried again today with 21.04, by checking exactly the time spent in the live session startup. After around twelve minutes from the boot, the Ubuntu logo disappears and I start to see console messages. Between those, there is one stating A start job is running for Snap Daemon (1min19s /1min 30s). This seems to suggest that there is a limit time of 1min 30s for that job, and if reached then the Snap Daemon fails to start. However, this time I waited a little more, and after around 30 minutes from the boot I could finally see the graphical interface of the live session. So I assume that this problem could be marked as solved, even if such a long time, especially compared with the relatively short one required when starting from usb, it doesn't appear to me as a normal behavior.

I assume moreover that this question can be marked as a duplicate of Boot version 21.04 from DVD extremely slow (and even impossible using Kubuntu) - but no problem when using USB stick