Hi Jeroen,
What browser did you use? Safari?
We tested on an iPad(not sure on iOS), and an iPhone 13 mini, iOS, 17.51 with Safari Browser,
Trying again today it seems to show results. However, the search button is all white no text “Search”.
I did update 3 plugins, Contact Form 7, Mesmerize Companion, and Backuply .
I will ask the customer to test again on her device.