Wrong scheduling times possibly related to outdated DST info

Your software
My Mautic version is: 4.0.2
My PHP version is: 7.4.11
My Database type and version is: MariaDB 10.5.12

Your problem
My problem is I live in the “America/Sao Paulo” timezone, and Mautic is sending emails one hour earlier than the intended scheduling time, as if we were in Daylight Savings Time, but we aren’t. My Mautic user timezone is set to America/Sao Paulo, and my local computer time is also in UTC-3, but all server related software is set to UTC time.

These errors are showing in the log:
No errors that seem related to this are showing in my logs, just some “Full authentication is required to access this resource.” authentication errors, probably because I keep my sessions open long after they expire…

Steps I have tried to fix the problem:
A quick workaround is to schedule emails to send one hour late, but this could lead to erratic behavior in the long run, since I don’t know why Mautic thinks I am in DST nor when it will stop doing it. This problem started to happen recently (late October, I think), so it will probably keep happening until February, as it seems to be related to the fact that Brazil stopped having DST since 2019. Maybe Mautic uses some outdated internal “zoneinfo” database?

I took a screenshot with the dates in various places where it could be going wrong, to try to figure out where Mautic is getting this “DST” info, but it seems to be all normal. Note that the scheduler dialog allows me to select the time I want, but when I save it Mautic instantly reverts to 1 hour earlier:

Also, other brazilians seem to be experiencing this issue since last year, across different Mautic versions: