Extract the boot image, place it in the downloads folder and then patch magisk to that image. It should automatically reboot the phone and installed the patched image. if it doesn't work, install the boot image in TWRP and then flash Magisk 18.1, some of these roms have a problem with 19.
Also, I don't think that I have tried that rom since Vidola reported that he fixed it. Are you still experiencing heat issues? Ideally your battery temp should idle at 85 to 95 F and 100 to 105F for the cores. If it is hotter than that, your battery idles higher than 104F it will be dead within 2 to 3 months, my daughters battery is near death right now. Because she removed magisk and didn't tell me that her phone was getting hot.
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I haven't had any app crash issues. But as you have said we have slightly different devices.