Yes there are many teething issues still open for this new helper.
https://github.com/home-assistant/frontend/issues?q=is%3Aissue+is%3Aopen+schedule
While fine to add “me too” posts here in the forum, do not do it on github issues as it makes it difficult for the developers to find relevant information. Just use the thumbs up button on the posted issue if you are experiencing it too.
I successfully created a schedule helper after the Sept update, but now that schedule is blank in the gui (though the .storage/schedule file looks correct). I cannot modify that schedule or create a new one (through the gui). I can drag a time block, but as soon as I click another empty block, the prior one disappears. In other words, Schedule is totally broken.
Tried renaming the “schedule” file and restarting. No joy.
Win 10 Chrome.
Same problem for me, seems it happens on every sundays.
I have the same issue. I can create a schedule, but cannot schedule anything on Sundays or it will give me an error that the time frames are overlapping - even when the sunday column is empty. I’m running 2022.11.3
Can confirm that. Seems the issue is easy to reproduce.
Just create a schedule for a specific timeframe EVERY DAY 
Regards
