Pretty sure it's more complicated than just that...once UA absorbed BN/SS/Liberty/Everybody elseA, there were all sorts of downstream catalogue permutations...the Allen Douglas sides that were originally done for UA itself were reissued on Solid State (and with no "Series" appellation appended). The dually named albums on that site of this nature all appear to be from non-US issuance. Here, they were straight-up Solid State.
Totally separately, Thad-Mel, who were always signed to Solid State itself, found themselves on Blue Note for an album, but for whatever reason the "Solid State Series" got appended to it, maybe something contractual.
Meanwhile in UA land, if you can see it:
Here's a band that had been recording with good success for Pacific Jazz as part of Liberty, now they're on Liberty as part of the "Pacific Jazz Series". So, you know things were getting all moved around and shit. I think it's safe to regard it as a mess.