I've owned two Pro1000II tuners and one Z-100A tuner. I purchased the Pro1000 because my Z-100A is near perfection but I wanted more power for digital and also an upgrade path, if I ever receive my Mercury IIIS. (I just wish the Z-100A would not sometimes take a several seconds to tune, so I could use it with the fragile FETs in my PreppComm MMX QRP CW transciever/decoder/encoder SDR--I had to replace the surface mount FETs once so I stopped using my LDG tuners with the MMX :( ).
My first Pro1000 had the behavior you described and several other problems storing and recalling previously stored frequencies as well as problems achieving a sub 1.7:1 (or even 2.0) SWR, unless I manually adjusted and stored (which it would often forget in a fairly short time). Manually adjusting L and C on the old one would sometimes only work in one direction; I'd go too far with button clicks and could not go back "the other way" with an opposite button click. I would then need to do a full forced tune (long press) and start over manually, having counted button presses the first time to not overshoot.
Sometimes my new 1000 still fails to find a sub-2.0 tune. (I don't really care much if it doesn't achieve the 1.7 setting, because I just want to keep my transmitter from rolling back the output, given that, AFAIK, standing wave coax losses between antenna and transmitter are invariant of the match achieved)
Cal -- AD8Q
