Connection to R2 bucket via Cyberduck fails


I used to connect to my R2 bucket via Cyberduck to upload larger files.
However since roughly 2 weeks this always fails with the following error message:

“DNS lookup for XXXXX failed. DNS is the network service that translates a server name to its internet address. this error is most often caused by having no connection to the internet or a misconfigured network. It can also be caused by an unresponsive DNS server or a firewall preventing access to the network.”

I have this problem from several PCs and my internet connection is definitely available.
So i have 2 question:

  1. How can I fix this issue? Unfortunately I am by far no professional in this field, so a dummy-proof answer would be very much appreciated :wink:
  2. Is there any online service I can use to load larger files to the R2 bucket as a fallback option?

Thank you so much for your help!