Conserve a favourite sticking point (4,3)

'conserve a favourite sticking point' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'conserve a favourite sticking point' is the wordplay.
I cannot quite see how this works, but
'conserve' could be 'jam' (jam is a kind of conserve) and 'jam' is found within the answer.
'point' could be 'p' (abbreviation) and 'p' is located in the answer.
The remaining letters 'lum' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

Can you help me to learn more?