Hi!
I'm using the web client in chrome on ubuntu.
I like to use unicode, and while many symbols like Π, π, α, ⊗, ∘ work, others don't. When I enter 𝓓 or 𝔻, for example, they appear in the window but when I reopen the note the next day, the 𝓓 or 𝔻 has simply disappeared.
I just tried in firefox, and it's the same issue.