As I mentioned above, there may be issues upgrading (Direct installing) Magisk from earlier Magisk that patched fstab for magiskinit injection due to (unexpected?) need to revert previous modifications:
The clue was this terse recommendation given to a user facing the same issue on a OnePlus device:
https://github.com/topjohnwu/Magisk/issues/6022#issuecomment-1163779264
before the issue was closed with no further explanation...
SInce then,
@osm0sis has asked
and Canyie finally clarified with this:
https://github.com/topjohnwu/Magisk/issues/6022#issuecomment-1165110166
So it's now confirmed that Direct Install will fail where previous Magisk installation (ie. method of injection etc) is no longer supported although a fresh install will work...
Hope this clarifies the reasons why you and others facing issues (bootloops etc) updating to 25.x (24303+) on 2SI devices need to
1) Do a fresh initial installation (patch/flash an original boot image) of Magisk, and
2) In some cases, eg where a custom kernel requires verity/verification disabled to boot, you may need complete Magisk Uninstall and OS booting w/o Magisk before taking fresh Magisk initial installation.
So:
Try patching/flashing unpatched image for fresh install...
Your
best chance (w/ Kirisakura kernel) would be to do complete Uninstall Magisk from app main page (or simply delete everything in /data/ADB and fastboot flash stock/unpatched images), then get ROM booting without Magisk using 3rd party means to disable verity/verification if needed. After this do a fresh install (patch/flash boot image from current ROM package) of Magisk...

PW