HTTP-Binding OH3 URL Encoding - Received "parameter is invalid" - Creating request failed: Conversion = 'm'

The problem is that you use an already escaped URL. %22 is the encoding for " and all %x are interpreted as “parameter number x” by the formatting that takes place in URL construction (to make the command and date available, this is also described in the documentation). If you “unescape” your URL, it should work (as you already found out).