Library not working with ESP8266 (client) and IIS or Filezilla (server)

[dimicamp]

Hi! I spend several hours trying to GET/PUT a file from/to a server that is working with other clients on my local network. I'm using a NODEMCU (ESP8266) as client and I already solve the PolledTimeout.h compilation problem. I keep getting the 451 error code and already tried to change the client from LittleFS to SPIFSF and several other things. As a note, my server is working fine when I use "ftp" from windows command prompt or "ftp:\address" from Windows Explorer or filezilla client. More details on the attached figure.