I was able to solve this finally. I had to add some new code to the plugin to bypass that ajax request. I have honestly no clue what was causing it exactly. Whenever the main search class was loaded, the error immediately appeared. However that search class file was not even in use, so it does not make sense at all. I feel like that class may have been used within another plugin, but it's nearly impossible to find out.
Eventually I give up on finding the cause, I simply added an exception to not run the plug-in whever the ajax request is done by the Essential Real estate plugin. That seems to have solved the map loading issue.
I will make sure to include this exception with the upcoming release, so you won't have to worry about it anymore.Best,
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