Sorry for you, the Fuel Strip isn't BMW's best implementation.
Did you connect-up the GS911 and did an auto-scan, were there any errors noted?
The non-flashing yellow is the warning-level, together with the flashing fuel-sign indicates the "regular" reserve-fuel situation.
The non-flashing yellow can only flash in red (or non-flashing red too, btw)
It can not and deos not flash in yellow AFAIK and according to the manuals?
I still think you should consider re-calibrating your fuel-sensor.
But you can first try to do the Piezo zap method, if that resolves it.
AFAIK the Piezo zap method never hurt the level strip, only resolves the impeding issue. Sometimes.
The actual fuel-level is only measured after a substantial distance has been traveld I'm told and then updated at some intervals.
And when you start the bike it merely just shows the last remembered state (level).
I do believe your calibration is off, but you could be right that your fuel-strip is on the verge of failing.
It is the micro-fractures and therefore change of resistance that is causing the infamous issue.
And the micro-fractures being caused by the fuel-strip floating around loosly on one (bottom) end.