mount -o rw,remount / works okay but mount -o rw,remount /system returns following error, 'APatch' is read only

[IntelligenceInside]

I am using latest APatch ver.

link to issue,
#843 (comment)

i am in terminal,

su
mount -o rw,remount / //works
mount -0 rw,remount /system //does not mount, i get the following error, 'APatch' is read only.

if i go through twrp, i reproduce the same issue as above.

Without mounting system, i cannot modify or edit or change permissions of files and folders.

Further info,

APatch ver. 11142
Kernel patch ver 0.12.2
Kernel ver 5.4.210
Sys ver 13
Sys linux status enforcing