2019 V4 air in rear brake

have you guys ever gone to ride ...and find your rear brake lever is much...then bleed the brakes and tons of air comes out.
it say for a week, we got 2 cold snaps nothing lower then 50, i go to ride and the lever is poop..
i did find that the brake pads had only a bit over 1/16inch per pad, so i replaced them..
rebled and all is well again, but i purchased another obstar after that debacle with my ex buddy sold mine.
and im gonna rebleed with the abs bleed feature just to be sure, front as well..
have you guys experienced anything like this on yours...
was it the worn pads let the pistons out too far and broke the seal (there was no brake fluid leaking out)
the brake fluid coming out was very milky so it had moisture in it, lots of it.
i bleed all my bikes every six months to flush out the fluid and air anyway,
but i have never had a master just be mushy from sitting from one week to the next even with really worn pads

Take the caliper off make sure its higher than the MC
Upside down
Hang a weight from the rear brake lever.

Now take a piece of silicone hose attach to the bleed nipple. Run the other end into a fresh can of brake fluid submerged.
Slowly loosen the bleed nipple.
Repeat as needed. Found this is the best way to bleed.

You can also crack the other end that runs into the ABS module to bleed air out there as well.

There was an update to the rear brake line to address poor pedal feel over time. I don’t know if it fixes the line possibly degrading due to heat or some other issue.

The p/n for 18-21 Panigale V4 is 61911531A. I have one on the way along with the revised reservoir bracket for the brake master.