Mount attempt receives SIGTERM from systemd (249) after unknown timeout

I am attempting to mount three mountpoints on a remote, parallel filesystem, using fstab. Periodically, one of the the three mounts will not succeed. An inspection of the journal suggests that systemd is sending a SIGTERM to the failing mount, approximately 69 seconds after the mount attempt. It is not clear to me where the 69 second timeout is originating, or configured.

Aug 08 17:37:25 vrr-20230804-cst-client-1 mount[883]: Mounting 10.114.96.165/fs3 on /mnt/fs3Aug 08 17:38:34 vrr-20230804-cst-client-1 systemd[1]: mnt\x2dfs1.mount: Mount process exited, code=killed, status=15/TERMAug 08 17:38:34 vrr-20230804-cst-client-1 mount[883]: SIGTERM received, quitting

The x-systemd.mount-timeout parameter is currently set to 300 seconds in the /etc/fstab entries.

Thoughts?