Very common. Power steering creates heat, cooling creates moisture
Read a bunch about it but cant remember where. I'll try to remember.
My 95 does it all the time overnight when the temp drops below freezing
Easiest fix was a fluid purge as you figured
96BBB 28K 3.42 Bolt-ons
95BBB 100K 3.73 383 New DD...already broke the 4L60E
95 Black WB4 Hole...ee...grail
95BBB 189K 3.08 Old DD