Hi, snsnse,Did you do a clean install? Your issues sound similar to what I saw on my klte after dirty-flashing from the previous install (CrDroid or LOS 18.1, I'm not sure which anymore). After the clean install the only thing that is still noticeable is the occasional lag/unresponsiveness after wake-up and before unlocking. Interestingly, CrDroid was actually giving me random reboots etc, so I'm a little surprised it works better for you. The current 19.1 build is pretty stable here.
I had to do a clean installation through TWRP since the running system was crDroid-v8.2. I also flashed the GAPPS (I first tried opengapps-arm-12L-nano-20220705-UNOFFICIAL.zip and then tried MindTheGapps-12.1.0-arm-20220605_111643.zip and in both cases the SIM card was not recognized). With crDroid-v8.2 I have never had unwanted reboots even though that build might not be as stable as LOS 19.1.
Is your SIM card really recognized at the very beginning of the setup or not? Do you own a Samsung Galaxy S5 KLTE (SM-G900F)?