Had to deactivate and uninstall RankMath SEO free plugin

I recently began having an issue on my website extra space appearing between the top header row and the main header row each time a menu item was clicked and a new page (or the same page) was loaded or reloaded, or even when a page was refreshed. The extra space was being created, it seemed, because a message was flashing in that extra space. The message flashed too fast to be read, but it was encouraging going pro.

Based on that flashing message, I posited the trouble might be the fault of a free plugin I was using. Through the process of elimination, I discovered the RankMath SEO free plugin I was using was the culprit. Deactivating that plugin eliminated the issue of the flashing message and extra space between the top and main header rows.

I have deleted the RankMath SEO free plugin from my website. I was using the most up-to-date version 1.0.210.

Unless this issue is resolved, I will no longer be able to use the RankMath SEO free plugin.