I’ve only taken a quick look at your report but it may be that you are affected by an upstream issue regarding docker and IPv6 that was reported here by @Emmanuel_perez & @sanderweel, take a look at the following suggestion by @sanderweel as a work around while we await the upstream fix’s filtering down to a Leap 15.2 update:
What leads me to this initial conclusion is the following in your reported errro:
Incidentally was your installer build using a 15.2 or 15.3 profile?