ASSISTANCE NEEDED: Bubbling of universal heat seals on LDV plates

Our scenario is we’re using ECHO ready 384 LDV plates and an A4S sealer with universal heat seals to seal them. The plates have ~5-6uL of compound in 100% DMSO in each well and we seem to be having seal bubbling issues upon thaw. These plates, in particular have been sealed for ~10yrs at -80C (and were sealed with the Agilent plateloc with the universal heat foil seal) but it’s not happening to all of them, just some and it’s sporadic. Also, across the plate (bubbles on the seal can be in the middle, or towards one end or the other or even most of the plate) We sometimes have droplets (compound or other(potentially water assumed)) on the top of the seals and usually, not always, these plates are ‘wet’ to some degree, but not always cross contaminated.
The process has been, thaw, if bubbles form, peel, check integrity, clean up/dry, reseal, spin and run. However, sometimes it takes another day to run a plate and during that time a plate at room temp(after being resealed and spun) will form the bubbles again (sometimes, but not always, in the same location on the plate). We were spinning for 2 min at 1000rpm and upped it to 3 min at 1000rpm. The integrity of the plates look good (not visibly melted from heat sealing)

Has anyone else encountered this scenario? How have you handled it? What could be causing this? Any suggestions to mitigate it?