You should be able to add wss:// urls to relay lists/sets. I'll have a look at merge, could definitely have broken something there. 🙈
You can when it's a fresh new list. You can't when your're editing an existing list and trying to add a new element to it.
can you send me the link of the list that you're having trouble with, just in case there's something odd going on with that speicifc list.
https://listr.lol/npub1xpuz4qerklyck9evtg40wgrthq5rce2mumwuuygnxcg6q02lz9ms275ams/10006/nevent1qqs828wvlvv3l8xm9xucw0jjmyeg9nywt6pyfx0q7xc62yeqjf92smgpzemhxue69uhhyetvv9ujumn0wd68ytnzv9hxgq3qxpuz4qerklyck9evtg40wgrthq5rce2mumwuuygnxcg6q02lz9mshs8fl3 and https://listr.lol/npub1xpuz4qerklyck9evtg40wgrthq5rce2mumwuuygnxcg6q02lz9ms275ams/10007/nevent1qqs9cqjy2xsdp747v3mjd0hnrf4k37km47fgkl905ach0c5cavm4keqpzemhxue69uhhyetvv9ujumn0wd68ytnzv9hxgq3qxpuz4qerklyck9evtg40wgrthq5rce2mumwuuygnxcg6q02lz9ms0q0yhc
This should be fixed now. Please let me know if you're still having trouble though.