I've had a few people try to buy my items from Depop however it comes up that there is an issue with my account. I contacted Depop about it and they said it is something to do with my PayPal account and to reach out to you to fix it. Can someone help me?
You need to contact customer services to resolve any limitation OR account specific issues. Click help / contact bottom left of Paypal pages for options available for your country.
Or have you considered contacting Customer Service via Facebook or Twitter? You can send them a personal message from their facebook or twitter pages. It's: https://www.facebook.com/PayPalUK and @AskPayPal for Twitter.
Advice is voluntary. Kudos / Solution appreciated.