problems with unconfirmed transaction of BTC deposits from wallet to wallet with fees paid in advance

Question

i have just started using a BTC wallet called Luno but have 2 unconfirmed transactions still pending while only the 1 transaction went through. 1st transaction was a test with a small amount being sent with no fees so is still unconfirmed but second transaction worked with the fees being paid upfront. my last transaction now worth a few more BTC and with all fees paid now also remains unconfirmed so i don't know how to get my transaction sorted? the source of my BTC wallet transaction is from the Bitcoin Core wallet which is up to now been used only from mining BTC.