The most common and most likely answer to this crossword clue is the 5 letter word THERE
I've seen this crossword clue in The Times
T
H
E
R
E
More clues leading to the result THERE
- Reportedly, those people in that place
- Soothing word from girl giving out sex appeal
- Sappers present
- Sappers in attendance
- Article on Religious Education in that place
- Word to comfort a number with energy at rock-bottom
- Article concerning on that issue
- Engineers told you so!
- Overheard: those people are in that place
- Extremely thorough before a sympathetic word
Buddy explains!

The straight part
We know that "on that issue" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case on that issue = there.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does THERE mean?
THERE noun- That place.
- That status; that position.
- (location) In a place or location (stated, implied or otherwise indicated) at some distance from the speaker (compare here).
- In that matter, relation, etc.; at that point, stage, etc., regarded as a distinct place.
- (location) To or into that place; thither.
- Where, there where, in which place.
- In existence or in this world; see pronoun section below.
- Used as an expletive subject of be in its sense of “exist”, with the semantic, usually indefinite subject being postponed or (occasionally) implied.
- Used with other intransitive verbs of existence, in the same sense, or with other intransitive verbs, adding a sense of existence.
- Used with other verbs, when raised.
- (in combination with certain prepositions, no longer productive) That.
- Used to replace an unknown name, principally in greetings and farewells
- Used to offer encouragement or sympathy.
- Used to express victory or completion.