[Question] pgwal increasing over max_wal_size

Hi all,

I am facing very unusual behaviour in our production postgres system
running on pg15 and deployed on AWS.
pgwal is mounted on a separate EBS drive with size of 100 GBs (on disk size
as seen from df -hT).
max_wal_size = 95 GB, min_wal_size = 1 GB, checkpoint_completion_target =
0.9

Issue is that pgwal size increased beyond 95 GB limits, and reached max
drive capacity of 100 GBs while ingesting huge data via copy insert.
Although the root cause of the problem to me looks like ebs volume size is
too close to max wal size and by the time limit was breached and check
point started, it was too late as WAL writing continued to happen and
reached max limit of drive, would like to know if someone has any ideas of
this.
Also, should we add a suggestion in doc regarding disk space and max wal
size as max wal size looks more like an upper limit which WAL is unlikely
to surpass(by large margin).

Happy to revert with more details if required.

Thanks,
Ankit