size of the cron entries

i have some users that are having issues when adding new entries to their crontab. is there a known limit on the size of a crontab file for a user and can it be adjusted? I've searched all over and can't find anything on this.

users issue

The problem is as we go on adding new cron entries, a strange thing happens. If the size of the cron entries (easily captured by crontab -l > mycronfile.txt ;) goes above 100K, the next day, new cron entries we had added disappear. Somehow the earlier crontab is restored.

Is there a limit on how much you can add to the crontab on this machine? If yes, can that be adjusted to be large enough? If not, what’s causing this?