Could this report duplicate MDEV-19916, which was fixed in 10.3.17?
mariadb-for-jira.log contains the following, which might match that bug:

2020-11-03 12:55:04 0x7fc7877fe700  InnoDB: Assertion failure in file /home/buildbot/buildbot/padding_for_CPACK_RPM_BUILD_SOURCE_DIRS_PREFIX/mariadb-10.3.11/storage/innobase/rem/rem0rec.cc line 820

InnoDB: We intentionally generate a memory trap.

InnoDB: Submit a detailed bug report to https://jira.mariadb.org/

InnoDB: If you get repeated assertion failures or crashes, even

InnoDB: immediately after the mysqld startup, there may be

InnoDB: corruption in the InnoDB tablespace. Please refer to

InnoDB: https://mariadb.com/kb/en/library/xtradbinnodb-recovery-modes/

InnoDB: about forcing recovery.

201103 12:55:04 [ERROR] mysqld got signal 6 ;

…

2020-11-03 12:55:05 0 [ERROR] InnoDB: Wrong owned count 11, 3, rec 7484

I cannot say this for sure, and this is a bug tracker, not a customer support platform.

As I understood from logs the rootcause of this behavior was described by these statements:

2020-11-03 12:55:05 0 [Note] InnoDB: Uncompressed page, stored checksum in field1 3123149291, calculated checksums for field1: crc32 3123149291/2544593751, innodb 4231256809, page type 17855 == INDEX.none 3735928559, stored checksum in field2 3123149291, calculated checksums for field2: crc32 3123149291/2544593751, innodb 3996955962, none 3735928559, page LSN 1315 2769137356, low 4 bytes of LSN at page end 2769137356, page number (if stored to page already) 469, space id (if created with >= MySQL-4.1.1 and stored already) 403452

2020-11-03 12:55:05 0 [Note] InnoDB: Page may be an index page where index id is 541398

2020-11-03 12:55:05 0 [Note] InnoDB: Index 541398 is `PRIMARY` in table `pxbjyhhu_main1`.`oc_promo_mailing_queue`

2020-11-03 12:55:05 0 [ERROR] [FATAL] InnoDB: Apparent corruption of an index page [page id: space=403452, page number=469] to be written to data file. We intentionally crash the server to prevent corrupt data from ending up in data files.

For me, it seems like server had an intention to update an index page, understood that some calculated result was invalid and tried to prevent the data corruption by crashing itself.
I also found the same trace when we had this issue half a year ago. The only difference was in the table name.

If you've restored from a backup and are running >10.3.17 we'd like to know if this happens again.