I'm doing a little research myself and maybe it's related to this compressor clutch not engaging as noted in the website below which sells the canned R134a?
Interdynamics Air Conditioning (A/C) Products How To Guide
It says adding refrigerant may alleviate the problem and make the clutch engage but according to my last measurement I had sufficient amount of refrigerant, already at the high end of the limit (45 psi measured at the low side as I noted in my original post above).
