Huge errors flow and memory leak!

Hello! First of all, thank you for very good and useful plugin!
I notice strange problem. My steps:

1. Open post
2. Clicking “Add to favorite link” (settings – display bottom of all posts)
3. Appers “Remove from favorites…”
4. Checking Favourites page – well done, favourite post has been created and correctly displayed, with working links such “remove” and “delete all favourites”
5. Refresh favourited post.
6. In bottom now displayed “Add to favourite” (Hmm… but post in favourites! May be WP SuperCache…)
7. Clicking… and woow!! Tons of errors in Code inspector, blank page with one fragment of layout, memory leak…

So, I cant deactivate WP SuperCache, but needed to add verify procedure – when clicking already favourited post. It is not special situation – anybody can by mistake click on “Add to favourite” link while post already in favourites, and get terrible situation with hanged browser, especially on slow machines with low memory.

You can check these steps on my project salsainrussian.ru. Site in ciryllic, but “Add to favourites”, translated to russian, bottom of post, with heart icon, and list of favourites – first submenu of first main menu.

Thank you in advant!
Regard

https://ww.wp.xz.cn/plugins/wp-favorite-posts/