Error message when trying to refund buyer

Description

I cancelled an order from a buyer on eBay and received a message from eBay telling me they have problems trying to refund the buyer and they asked me to refund the buyer myself directly through PayPal. I have tried to refund the buyer yesterday on my computer but got the error message ‘We can’t process any refund right now due to technical reasons. Please try again later.’, I have tried again today on a different computer and I have got the same error message. I am thinking it may have something to do with the fact the buyer paid in Euros but I had a GBP balance only? I have my settings enabled so that any transactions I receive are automatically converted to GBP. Today, I have been trying to look up the solution and I saw that someone had a similar problem and they were suggested to open a EUR Balance, so I did go into my Settings and added the EUR currency and it oddly says I have a negative balance which is very confusing to me as this is my first time with a EUR balance and I have always selected for transactions to be converted as I mentioned. Also, I have never made a payment myself in EUR either and this is my first time having to refund a EUR transaction, all payments I have received in the past have only ever been GBP payments and it is only recently people have been paying with EUR because I now have listings on some EU eBay sites.