An agent makes anything from 3% to 10% on any players contracts, so pushing moves is not always in the interest of agent client relationship. So if Beavon is on decent money that his agent knows he can't get somewhere else, it's sit in and let the existing deal run out until another opportunity comes along.
Beavon, is not going to walk away from 100,000 or whatever he is on because it upsets a few fans. He will train, complete his contractual obligations unless told otherwise which will be due to a pay off, loan or a contract offer from another club. The fact he is still here may show others are not willing to match or better his current deal.