Comment 4 for bug 1842333

Thank you for providing additional information, however this seems to be the new configuration you are using with ipset and as such, it doesn't provide the necessary information to reproduce or triage this. You suspected that this might be a concurrency issue, but as of 8387ae082a362b00ad339293ec2ad547338b9209 (in 0.36, available in 12/2018), concurrency is supported so long as you use the 'ufw' command to add rules to the ruleset.

How were you adding the rules and what is the output of 'ufw version'?