Thank you all for your messages.
Usually, when an exchange does that, it's because they detected suspicious activity with your transactions or account. Have you tried calling them?
Yes, I think this is it. But I can't figure out what, since I've apparently never violated the regulation.
However, I have received some emails from Coinbase support where they have asked me a lot of questions, which I have answered.
In the last email they told me that I have to wait 5-7 working days for the problem to be resolved. I hope it's like that. The fact is that I needed the money now, not in 7 days.
They tell me that if I can't withdraw via PayPal in 7 days I can do it using another method. But at the moment everything is blocked: I can neither buy nor choose another payment method, nor send cryptocurrencies to an external Bitcoin address. In short, I can only deposit and convert cryptocurrencies into Euros. But I can't withdraw.
I keep you updated. I hope everything works out but I'm not very hopeful.