Items disappear in Paper UI when using MAP transformations

Setup, Configuration and Use Runtime
1

Just started migration from OpenHAB 1.8 which I’ve been using for over a year without problems.
I installed a recent snapshot (build #672) of OH2 using Docker on a Synology NAS.

Following the migration guide from 1->2, I noticed that my items disappear in PaperUI and Habmin as soon as I start using MAP transformations. PaperUI gives an error 500, however no errors are logged in the karaf console. Also the Items still work properly in all user interfaces.
For configuration I used my OH1 text based files, modified for OH2.

The items re-appear in PaperUI/Habmin as soon as I remove the transformation rule from the items file.

Example of the item:
Switch iPhoneBOnline “Bram [MAP(presence.map):%d]” (gPresence) {fritzboxtr064=“maconline:xx-xx-xx-xx-xx-xx” }

I also noticed that the transformation by itself is working properly in the UI’s.
Anyone any idea what might go wrong here ?

2

Just found out when changing [MAP(presence.map):%d] to [MAP(presence.map):%s] and adding transformations for ON and OFF in my map file, the items no longer disappear in PaperUI/Habmin.