Hi,
Thanks for the details!
I have tested the layout, but I get the correct output on all types of mobile devices: https://i.imgur.com/owdui9o.png
If it does not happen all the time, then it means you may have some sort of an issue with your cache. Since you are using multiple search bars for different device types, then make sure to have a different cache for each device.
I believe all cache plugins have an option for that, usually is called “Cache Mobile” or “Separate cache for mobile” or something similar.