GPS tracking problems - any advice? [Locus Map Classic on Android OS)

I recently updated my phone to a Samsung Galaxy A54 (One UI V 6.1) and since then am encountering problems with my GPS signal when recording my tracks in Locus Map Classic (V 3.70.9).

I used to record while having my phone in airplane mode, battery saving options enabled, no WiFi, no mobile data and only using it once in a while when getting to crossroads, junctions, etc.

Every time I use the app now and turn on the screen to do so, my GPS takes some seconds (about 15 to 20 seconds on average) to get my position and resume the tracking – which then is totally off course.
Also I tried multiple combinations of settings for my phone – airplane mode turn off, WiFi turned on, battery saving options disabled, only airplane mod and WiFi off, either with using Samsung device modes and also without that.

Furthermore, I made sure that Locus (and also BR router) isn’t shut off when the screen is turned off, gave every explicit accesses to those apps and executed all the steps mentioned here:
https://docs.locusmap.eu/doku.php?id=manual:faq:gps_lost_fix_android6.

I uninstalled and reinstalled the apps as well as all the offline maps. I reset my GPS via Locus Map Classic, deleted all temporary files and emptied the cache, too. Also using a third-party app such as GPS Locker didn’t work for me.

All the mentioned apps as well as my OS are up to date.
Right now I’m quite at a loss at what to do since I’m regularly hiking/biking in regions with little to no constant WiFi-access and therefore depend on tracking my location via GPS.

Do you have any suggestions as to what I might could do know?

I really want to keep using Locus Map Classic since for hiking I need to see the shades of elevation for the terrain.

Thank you in advance!