There are a lot of issues with transfers for me. Especially with low rated players I could get 15-20 offers for a player in the one transfer window and he rejects everyone of them.
Sometimes when I negotiate for players I offered slightly below their value and they turn around and massively increase their prize. Fir instance I offer 2.75 million for a 3 million player and they come back and tell me they cant take lower than 17 million.
And finally negotiate a new contract with a player and he accepts it but it doesnt update and he leaves on a free transfer.