Xray Test Sets loose relation to added tests after editing custom field version

We have introduced a new custom field version (label) in Xray issuetypes which gives us the possibility to store revision information about the issues.

Test Sets loose the relation to Tests which have been added to the Test Set when a new value is entered into the empty custom field version. This Bug is realy serious because we have Test Sets with douzens of Tests "in the right order". (I think the same problem would also appear with other custom fields.)

Steps to reproduce:

• We have extended Xray Test, Test Set, Test Execution and Pre-Condition with a new custon field version (label).
• Create a new Test Set
• Add some Tests
• Edit custom field version, e.g. set version to v0.9

Expected result:

• Test Set has version v.0.9 and relation to tests

Current result (bug):

• Test Set has version v.0.9
• relation to tests has been lost