The segmentation fault of Postgresql 9.6.24

Hello hackers,

Our prod databases are still PG 9.6.24. We have one primary plus 3 stream
replications that are all working well for a long time. However, when I
promoted one standby database to the primary role, we the the below error
message from the PG log:
=======================
2023-12-01 06:57:35.541 UTC,,,1553,,6569738f.611,639,,2023-12-01 05:47:59
UTC,,0,LOG,00000,"server process (PID 31839) was terminated by signal 11:
Segmentation fault","Failed process was running: UPDATE xxxx SET
employee_id = (9489910) WHERE id = (1162120221)",,,,,,,,""

Here is the message from dmesg:
=======================
[ 3676.406247] postgres[27789]: segfault at 0 ip 00005618bf79bfe4 sp
00007ffcd9a75dc8 error 4 in postgres[5618bf3db000+3f7000]
[ 3676.406265] Code: ff ff 48 83 c2 40 ff d0 e8 19 9c ff ff e8 44 0f c4 ff
0f 1f 40 00 f3 0f 1e fa e9 27 be cc ff 0f 1f 80 00 00 00 00 f3 0f 1e fa
<0f> b6 17 89 d1
83 e1 03 80 f9 02 74 0f 80 fa 01 74 0a 48 89 f8 c3
[ 3715.937850] postgres[27928]: segfault at 0 ip 00005618bf79bfe4 sp
00007ffcd9a75dc8 error 4 in postgres[5618bf3db000+3f7000]
[ 3715.937858] Code: ff ff 48 83 c2 40 ff d0 e8 19 9c ff ff e8 44 0f c4 ff
0f 1f 40 00 f3 0f 1e fa e9 27 be cc ff 0f 1f 80 00 00 00 00 f3 0f 1e fa
<0f> b6 17 89 d1
83 e1 03 80 f9 02 74 0f 80 fa 01 74 0a 48 89 f8 c3
[ 3732.278367] postgres[28212]: segfault at 0 ip 00005618bf79bfe4 sp
00007ffcd9a75dc8 error 4 in postgres[5618bf3db000+3f7000]
[ 3732.278384] Code: ff ff 48 83 c2 40 ff d0 e8 19 9c ff ff e8 44 0f c4 ff
0f 1f 40 00 f3 0f 1e fa e9 27 be cc ff 0f 1f 80 00 00 00 00 f3 0f 1e fa
<0f> b6 17 89 d1
83 e1 03 80 f9 02 74 0f 80 fa 01 74 0a 48 89 f8 c3

Error 4 is the error related to unmapping memory. But the database works
well for long time as the standby database. After it was promoted to the
primary role, no memory parameter change at all.

Could you give us some hint where to fix this issue?

Regards,

Kevin