Since your pressures are equalizing in the normal timespan and normal pressure range the compressor is likely inefficient:

Normal Run Pressures:
R134: (Low) 5”HG – 5PSI (High) 85 -110PSI
R600: (Low) 10″HG – 15″HG (High) 45-60PSI

Inefficient Compressor

Low Side: Higher than Normal
High Side: Lower than Normal

Overcharge

Low Side: Higher than Normal
High Side: Higher than Normal