This is an issue that is affecting a lot of people, so it deserves its own sticky topic. There seems to be an Office + Windows update that affects some COM add-ins like MySQL for Excel when trying to render some controls, although the problem is not specific to the latter.
As of now, no clear information from Microsoft states what specifically causes some controls to not render at all, my best suspicion is that it is related to owner-drawn custom controls and/or newer DPI scaling mechanisms introduced in recent versions of Windows and Office.
There is an official article from Microsoft related to this problem:
The solution offered in the article above is:
** To resolve the issue, update Office to version 1808, or a later version, and update Windows to version 1809 or a later version.
There is also a workaround offered in that article, that is consistent with the one offered by some fellow users:
** Until Office and Windows have been updated to the required versions, you can configure the When using multiple displays setting in Office to Optimize for compatibility. The issues should not occur in compatibility mode.
Another workaround other users have claimed to work is:
** Uncheck Enable Protected View for files originating from the Internet, in the Trust Center Settings within the Excel options.
Hope this resolves the issues you are having.
MySQL on Windows Team