I have been in contact with our ESRI provider who has sent the bug further to ESRI, hopefully it will be fixed very soon.
Case: I have a simple asset inspection app I am building as a proof of concept.
Points on map will display different colour depending on when they were last inspected.
It works fine in ArcGIS collector. But in Field Maps it is not. It seem to ignore UTC time and run with local, always.
Field Maps
Collector
You can see how date time is handled differently. This is what is shown in my Custom popup. First picture is from Field Maps, Second Picture is from Collector. Since I am using "Time from last created" to symbolise my points, this is problem for me.
Notice how now() and Timestamp() is returning the same in Field Maps....