Thank you for the proper information and the details.
I have found and fixed the problem. It was an older image cache class causing the problem, which I have disabled. This has already been fixed in the latest version – but you don't need to update if you prefer using the one you have.
In case you decide to update, to prevent issues please read the Ajax Search pro 4.9 change notes and the safe update notes section, because the plugin version you use is significantly older than the current one.Best,
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