A French chaise longue with fourth and fifth panel switched? Bother! (8)
I believe the answer is:
unsettle
'bother' is the definition.
(thesaurus)
'a french chaise longue' is the wordplay.
'a french' becomes 'un' ('a' in French).
'chaise longue' becomes 'settle' (I can't explain this - if you can you should believe this answer much more).
'un'+'settle'='UNSETTLE'
'with fourth and fifth panel switched?' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for unsettle that I've seen before include "Faze" , "Disturb, disconcert" , "Disrupt" , "'Disturb, unnerve (8)'" , "Trouble" .)