Yep, that snippet in place prevents the error message and the search can display the results again. However, they are now displayed in the original language.
I looked at the XHR response via the browser console. As you said, Weglot translates them and in doing so, it seems to misplace an apostrophe in my case. A corrective translation rule in Weglot seems to me to be the most promising solution too, however I cannot find this XHR response in the translation table in my Weglot dashboard. I will contact Weglot support with this information.
Thank you very much for your support.