Only COLD water gets into the tub.
Hot water comes out of the hot-water hose. Cold water comes out of the cold-water hose.
The water inlet valve is less than 9-months old: both screens are clean, the passages look clean and the continuity tests OK. Can the water inlet valve be mechanically defective?
If the water inlet valve is working correctly, what other part(s) might be causing the no-hot-water problem?