We have another problem in 2.8. We have record filter that is set with the ">" argument in 2.7. When opening the same DataManager Record Filter block in 2.8 the argument is changed to ">=". This is causing problems.
Thanks for reporting. This issue was caused by an issue reading the legacy value in 2.8. This issue has been fixed. The fix will be available in tonight's 2.8 release (b1098).