if you are getting used to blowing again you might have been making an unclear, weak F anyway, so having RH3 down also, might not have made much difference initially for you to be aware of.
(You probably know, practicing playing just one note and holding it steady as a long held note is extremely beneficial for your diaphragm/lungs, air stream, ear acuity, lip tension, sound, timbre, pitch, clarity, volume practice, stamina and so on. Listen to the nature of the sound of the note you are producing and you will become aware of different fluctuations in some of these as you play it.)

Best wishes for your playing and practicing.
(Remember to set global transpose to Eb instrument, information in the tutorials)