Nice G on adding the links to the wiki. Ty!
So this afternoon, I took it back to the store and explained the situation to the gent who rented it to me. He then went online and I believe called the Fender rep and they got it sorted out.
We quickly and seamlessly updated the firmware and transferred the tone patches using the PC desktop app via the USB to micro USB cable which is hooked up prior to turning the LT on.
We still don’t know if the phone/tablet apps will work or not. I kind of doubt it.
Either way. With that issue taken care of and now that we know that the amp is in good order I then decided to buy it. The dealer also took the rental cost out of the price too so a double win and a NAD for me lol.
So after having 2-3 month rentals of the Studio 40 & Rumble 100 but never could quite pull the trigger on them I’m now the proud owner of a Rumble LT25.
As it is with its stablemate the Bassman 25. It’s a nifty little amp with a tone bigger than its humble wattage and 8” speaker would suggest.
The cleaner presets such as the Studio Clean and Rumble sound very nice for a core tone. Then there’s the cornucopia of options for tweaking from there. Fun stuff!
It’s somewhat a bit limited in flexibility compared to the Studio/Stage series in that you can’t juggle the order of effects but or put multiples of a given type of pedal in the chain but otoh this lessens the time spent in tweaker’s limbo too. Fwiw there’s also no DI or effects loop either. I have no need for them here.
The only complaint I have irt the available patches is that there isn’t a proper envelope filter to be had which is hugely disappointing as I loved using them on the Studio. It also seems kind of pointless to only have one EQ available for the EQ pedal too. Now I just need a footswitch and another very portable but inexpensive device that will run the Tone Desktop App as I guess the regular Fender Tone app doesn’t work with the LT25 and I don’t want to be messing around on my son’s PC either.
Regardless, it’s a blast to use and imo a very good bang for the buck. Highly recommended so far. Very very happy with it.

So do I get a Rumble club member number now finally at long last?
Also, Pics or it didn’t happen...
Yeah, a palace my place isn’t but at least it’s paid for and things are getting better again for the economy and such so repairs are coming soon. Calling the plumber today actually to get that end of things taken care of. It’s been a rough stretch but things are looking up.