Add an connection like this and click on "Save"
Then just click on "Add Connection". When you now try to connect nothing is working.
If you Edit the connection you see, that the Port was set on "21" instead the saved "22"
Sync is enabled in this setup.
Thanks for reporting this issue, I can confirm this has now been corrected in v3.4.7 👍️
The port was initially being parsed as a number but when changing the value in the connection dialog it was being parsed as a string... however when editing later any port with type number wasn't being populated only ports parsed as a string was then being populated upon editing and connecting.