Would I post that specific string of characters, behind the -Certificate argument?
I also noticed, in one of the links you provided, that the -explicit argument is only for use with FTPS protocol, and in this version of the code I'm working on simple FTP, although I will be switching to SFTP or FTPS once I get the simple FTP version working.
When I removed that argument from the code, it looks like I was able to connect, but received another error:
< 2019-04-18 10:48:19.320 Script: /UID/Downloads/Test
> 2019-04-18 10:48:19.320 Script: lcd C:\Work\ClientFolder\SendFiles
< 2019-04-18 10:48:19.506 Script: Too many parameters for command 'lcd'.
. 2019-04-18 10:48:19.507 Script: Failed
. 2019-04-18 10:48:19.507 Script: Exit code: 1
. 2019-04-18 10:48:19.515 Disconnected from server
Note: "ClientFolder" represents a folder that looks like: "\Client Name\2019-04 SFTP\" which does include a space in the first name