Hello @kenken and thank you for being a part the Community!
I apologize for the late response. Were you able to get this issue fixed and do you mind sharing how for other end users who may experience this issue?
If you were not able to get the issue fixed, do you mind sharing a screenshot of the issue so that myself or another end user can assist as best as we can? I was able to locate a help article with more in depth techniques for troubleshooting FileZilla FTP Connections. The article did mention various reasons as to why you may not connect and has different suggestions to try.
Again I do apologize for the delayed response and I hope you have a wonderful day!