You can download previous versions of RW7 here: https://realmacsoftware.com/rapidweaver/releasenotes/
Maybe try reverting to RW 7.2.2? 7.3 seemed to create FTP problems for some users. Just trash your 7.3 version and put 7.2.2 in your applications folder. Might be good to re-start your Mac as well.
Also, check what version of RW you are actually using by clicking on “About Rapidweaver” in the top menu under “Rapidweaver 7” and make sure you are actually using 7.2.2