Delivery date issues

Hello everybody,

The delivery date in the order card will not go any further then September.

Example: if you choose a date eg. 10th of October, it jumps back to 10th of August.
Other example: if you choose 20th of September it jumps back to 20th of August.

This date will be printed on the order replies. So when someone orders in September, the delivery date is in August…?!

After searching for the reason for days, checking all the files on the server, searched on the forum, etc. I decided to remove Dolibarr and install it again.
The database and the documents files were back-uped and replaced after the new installation.
Problem still occurs.

Dolibarr version 18.0.0

Can somebody help me with this issue?

Many thanks,

Bou