I had this happen in a 47J in Tassie in mid winter, snow, ice, etc. The engineer deglazed the clutch after 1 week. In PNG & Darwin this happened in a 3B1 & in a G2 in Sydney; I can't remember how long we put up with it as it does get worse, probably 2 weeks at the most. I think it is caused by poor engagement technique such as incorrect throttle control. It doesn't take that long, winching up the trannie gives you access to the clutch.
I wouldn't like to suggest what you do as all this happened so long ago!
Send me a private msg if you like.