PN1,
I would not worry about bubbles under the pump lid unless they cause other issues..
If the water in the pump basket keeps going down to where the pump is running out of water, that would be an issue.
If the air in the pump basket continually gets pushed into the filter and then out into the pool that would be an issue.
I have three IntelliFlo pumps, that all run at 1200 RPM most of the time. All three have some bubbles under the pump lid. I set up my automation system to ramp up the pump speed to 1800 RPM, a couple of times a day for an hour, or so, just purge most of the bubbles. I have been doing this on all three pools for a total of over 25 years and have not once had any issues with bubbles in the pools or the pumps running out of water.
For me anyway, I don't see a few bubbles under the pump lid as a problem.
Thanks,
Jim R.