My watch automatically updated overnight and now I'm experiencing this as well. There is also an even longer lag if I press the start button to bring up the activity list to select an activity. It didn't do either of these things on the previous firmware.
If you connect the watch to the desktop and you eject the GARMIN disk so it exits from USB storage mode in order to be able to control the menu you will notice that while the watch is plugged in to power and charging the lag disappears no matter which custom watch face you select and try to navigate through the widget cycle. This indicates to me that this lag has to do with the transition time from low to high power mode which for some reason was prolonged by upgrading to 9.20. It is obvious that when the watch is plugged in, the two power modes are abolished. Maybe someone from Garmin can verify this and explain it more precisely.
Same issue with a custom watch face - lagging when switching to other screens. I'm using SC7 face, but I tried some other ones and all of them lag compared to 8.0 firmware.
