Solanoid stuck in off - Intermittant XC90
 

Hi, I have an xc90 2006. Had recent diagnostics done regarding transmission fault, to find its a solenoid stuck in off. Car still drives fine when the issue arises. My question is due to the conflicting advice i am receiving from garages. One said this is the slow road to death for the transmission and theres no point fixing the solenoid, I need to either replace with secondhand option or get mines reconditioned. Another said fix the solenoid and if further issues happen we can replace with secondhand transmission box, because they are fully checked before they are sold my risks would be minimal (also get a 1 year warrenty)
I called the company that recondition your own box to cancel appoint and he thinks the advice on fixing issue was bad, as the issue is not the solenoid on its own theres a bigger problem causing it to stick? I am feeling very confused now as to what would be best solution, its an old car and i feel that spending 3k on reconditioning transmission is too much, however we dont think its for the grave yard just yet?!! any advise would be helpful!