I use conceal and write some LaTeX files in the GVim 8.2 editor on windows. The conceal works fine most of the time but it is unable to display certain characters like ∈ and ⊆. It shows a box with a question mark instead: something like [?]. My encoding is set to utf-8 so I do not know why this is happening. This does not happen in Vim on Linux probably (I saw a youtube video and there these symbols were properly displayed). Is it possible to correct this error?