[Bug] lsp-ui-doc-show displays buggy and often needs multiple attempts

[ianyepan]

As titled, when invoking lsp-ui-doc-show or lsp-ui-doc-glance, I often need multiple consecutive attempts until it correctly renders the child frame. Here are some screenshots to demonstrate:

First attempt invoking lsp-ui-doc-glance (unreadable)

Second attempt invoking lsp-ui-doc-glance (partially readable)

Third attempt invoking lsp-ui-doc-glance (correct expected output)