well, i could be wrong but lightning can do this stuck thing, so i figured it might be that

sorry i forgot to ask, if it's an on-chain payment and it's stuck that means the fee was not high enough for the current fee market

you may be able to bump it with a Child Pays For Parent or RBF

hopefully someone who knows better than me will pop up to help you out

btw, make sure you keep the key associated with that transaction just in case it gets resolved