i found this happening when i had a loan offer come i for my player but changed the wage split to (100%/100%) and to a mandatory fee of £30m where after it was accepted the wage changed to (40%/40%) and the fee to £27m
QUICK FIX !!!
what i found worked was changing the deal to non negotiable and private (did both not sure if they both make a difference) and also didn’t suggest transfer but made a full offer and wait for them to either accept or decline