Uptime: Reports site down when Optima Express IDX plugin is active

My site is reported as down both Hub’s Uptime tab and Hummingbird Uptime.

First I thought that the issue was caused by Defender because when having all plugins active on the site and only deactivating Defender the issue wasn’t there, but after running a plugin conflict test on the site I’ve confirmed that the issue is also related to having Optima Express IDX plugin active.

I need this plugin on the site because it's what allows the clients to show their real estate properties and searches on the website and also I have other sites that have this plugin installed too and would like to add Hummingbird and Defender to them, so if you can find a fix it would help me to not have the same problem with them.