I recently bought Doom 1 on GOG for $5.99.
This transaction showed on my bank statement as two separate charges.
-$5.99 PAYPAL *GOG [11 diget number] POL [last 4 digets of my debit card]
-$0.17 FOREIGN FEE JagielloXska 7 [same 11 diget number] POL [same last 4 digets of debit card]

I have never seen this 'foreign fee' before, especially with what looks like someone's username associated with it.
Is this normal? Should I dispute the charge?

Thanks

It may be a tax/VAT charge applied separately to the order. If it's a completely unrelated charge to the GOG purchase and one that you don't recall making then I would definitely be disputing it were I in your position.

Sounds like a foreign transaction fee that your bank charges if you use a different currency. I'd probably say it needs checking with your bank to see if they did indeed add it and if so then why.

I used to get these back when GOG only traded in USD.