I was finding I could not update the cross-avr utilities or even download them with wget on Tumbleweed.
The symptom was that they would timeout after sitting there for a long time and I would have to enter "i" so that other packages could proceed or alternatively use "zypper al cross-avr-*".
I could download them on Leap 15.3, scp them across and install them.
The repo baseurl started with http://, changing it to https:// solved the problem.
I notice there are still a number of repositories using http://, none causing problems currently.
Is it time to change all URL's to https://?