Cleaning threads can help, but it could also be bad internals in the back end, or a weak (old) battery.
When cleaning threads, be sure to do the female threads inside the body where back end screws in. I usually use q-tip with light iso, but recently tried a small alcohol wipe (wound prep type) wrapped on the round end of a chopstick, swirling around inside. I got more oxidation off (Ti units are more prone to oxidation) than I had gotten with a q-tip.
I have also ordered a small bottle of De-oxit 100 to finally give it a whirl. We don't hear much about it these days, I think it's probably a great contact cleaner, and those back end threads are contact points.
https://www.amazon.com/gp/product/B07F8ZX2GD/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Back end is slightly less hot after cleaning with iso, but actual current is much improved. Before I was often getting red blink battery indicator, but a quick turn back and forth (of back end, not temp dial) would get me more hits. Now I'm not getting the red blink as often, and less flutter of the blue during use.