Issue when using Quick Edit feature

Hi everyone!

I am running 7.10.13. on a regular stack with Apache(2.4.25) and MariaDB(Ver 15.1 Distrib 10.1.37-MariaDB) on Debian 9.7. Only customization are added fields to the Cases module via Studio. Checked the syntax of php files in /custom/modules/Cases/.

When editing a case using the quick edit feature (double clicking in a filed), most of the times additional fields are being edited with unchanged values. Changelog than shows up to 4-5 other edits in the same second with equal “Old value” and “New value”. This heavily overcrowds the Changelog and interferes with my calculated fields as the workflow thinks someone edited the field. Those “ghost edits” are distributed throughout the layout. It happens in List View and in Detail View. Obviously not in Edit View. Happens for all users, both English and German language packs.
It does not seem to be a general bug, unfortunately rather a specialty of my installation. First appearance was months ago and seen as a rather aesthetic issue. But by now using Changelog is very cumbersome and we started using calculated fields which simply does not work with those edits(date time is being saved).

suitecrm.log:

Fri Feb 15 12:27:29 2019 [20294][1][FATAL] SugarBean::populateDefaultValues $field_defs should be an array

Apache error.log
No entries when saving. When opening Changelog:

PHP Notice:  Undefined index: before_value_string in /mnt/crypto/www/suitecrm/modules/Audit/Popup_picker.php on line 183

Screenshot:
https://pasteboard.co/I1gDGNz.png
In the third row you see the added text “TEST TEST TEST” which also triggers the other two edits with unchanged values.

Running our of ideas. Any help is much appreciated.

Best,
Jan

PHP version: 7.0.33-0+deb9u1