This relates to Trados Studio 17.2.10.19084

When you filter segments in Advanced Display Filter, for example to display (Not Translated AND Draft AND Unlocked) and then attempt to run Find and Replace containing Regular Expression, the "Replace All" button does not work as expected. The issue is that Replace All only works in the current segment (where the cursor is placed) and does not proceed to any other segments. One would expect that Replace All would go through all the segments filtered rather than just current one.

This happens for any regular expression but for me it happens specifically for this one:

Find: (^[\p{L}\p{N}]| ([\p{L}\p{N}]|ds\.|art\.|rys\.|\d+|\d+,||\([\p{L}\p{N}]|[\p{L}\p{N}]\))) 

Replace All: $1

Where $1 is followed by a non-breaking space (which cannot be displayed here)

The purpose of this expression is to "glue" single letters, numbers and certain abbreviations to the word the follows in order to ensure that such single letters, numbers and certain abbreviations are not left at the end of line.

It would be nice if this bug was addressed in some update :-)