Cron jobs have a next_run time of 2020-01-01 00:00:00

Hello,

We're a new user of ISPConfig and notice our stats weren't getting updated.

ISPConfig Version: 3.1dev
OS: Debian 10

After some debugging, I found I could only run the job if I ignore the next_run date.
I then found out all cron jobs have a next_run time in the database of 2020-01-01 00:00:00
This time come backs after setting it manually to a past date, after running cron.php

I checked the system time and it's correct. I checked the unixtime output of MYSQL, and it is also correct. It is 1566856952.

So, I guess the error is in cron.inc.php function "getNextRun($vDate) {"
Have you seen this before?

Variables like $iCurMinute and $iNextMinute and $iMinute and $iNextHour all appear blank when printing them to the console, and $iYear increments from 2020 to 2024

Thank you