Trouble with DateTime values for Summer-Wintertime transition

In my application I have an attribute DepartureTime that is not localized. The user has a timezone set to Amsterdam time, UTC+1. Project time-zone is also Amsterdam. The attribute contains the date component that is derived from the general startdate of the schedule and a time component that is requested from the user in an input field. The input field only requests the time component of the attribute e.g. ‘12:39’. Now I have the attribute set to UTC ‘2021-10-31 00:00’ (the transition date for summertime to wintertime). My input widget shows ‘00:00’ (correct). When I enter ‘01:30’ and then leave the field, it changes itself to ‘02:30’ (without program interaction!). Why?? It appears that times from '01:00’ until '01:59’ have the same  problem. (when entering 00:30 or 09:00, it gives no problems).  When I put an OnChange microflow on the field, this behaviour persists. The variables dock displays: UTC = '2021-10-31 01:30’, Session time = '2021-10-31 02:30  +0100’. The expected behaviour is that is will not autonomously change the value. Further processing is up to the application. How to change this behaviour?    
1 answers

Check your default timezone via Settings (Project) > tab Runtime > default timezone.