I'm on the beta version and here are the issues that I notice. The first horizontal line make the text bold instead of making a line. I think that you cannot "close" a subscript or a superscript. I find the copy block button a bit too large. I think that you used the wrong spoiler tag.

Here below my test on the beta version:

!This is a spoil!<

E~x~ = x^2

Any way, I give my energy to the sync developer and testers ༼ つ ◕_◕ ༽つ

I am not yet subscribed in the Canada community in lemmy.ca, but I should ~~not~~.

You miss 100% of the shots that you don't take

Edit: The Canada@lemmy.ca link don't work. What is the proper way to link to a community in lemmy?