Hello All!
The above subject is discussed on several different posts but I am listing this post to highlight the same issue that also occurs with my Thrustmaster HOTAS Throttle Quad.
Aircraft affected: All Native and 3rd party aircraft that have a heading bug and Altitude selection setting!
Peripherals affected: Thrustmaster Warthog HOTAS Quad and like many of you I can confirm it’s also happening with my Honeycomb Alpha Yolk!
The Issue: In a nutshell is that when I use my mouse wheel to either increase or decrease the heading bug OR change the Altitude Window higher or lower whilst using a toggle switch thrown to activate a system/light/heater (for example; when I turn on the landing lights using a mapped switch on my HOTAS or my Alpha yoke), the mouse only scrolls the heading bug (up or down) in increments of 10 degrees and the altitude window by 1000 foot increments. Once this switch is changed to the previous state (that has not being mapped), the heading bug can then be changed (up or down) in increments of 1 degree and the altitude window can be changed in increments of 100 foot, as it should be.
Also, I have noticed that in addition to the affected heading bug and altitude window setting above, this increased default setting also affects changing the Speed bug, HSI Compass and Compass Rose (that I’ve noticed).
Good news!! Whilst we would all like the good folks at Asobo to fix this please, I have this morning found a really simply work around. To make a change to the effected instrument, hover the mouse as you would over the knob and instead of using the wheel, click and hold the left mouse button. The first movement the bug will make is unfortunately the 10 degrees, 1000 foot, or 10 knots but then the next and subsequent increments will be 1 degree, 100 foot or 1 kt! This is how it seems to be working on my setup.
Lastly, this issue doesn’t seem to manifest itself with all items controlled with the toggle switches. For example, with me, when using it to control the beacon, its fine. But not with the landing lights! Go figure 
Cheers!!