Used ADAU1772 codec on our board, using in Ain0/1 (Stereo input J2 jack) and HPOUTLP/HPOUTRP (Stereo output J8 jack), simple pass-through audio (DSP is not used).
Observed if plug/unplug headset at output stereo 3.5mm jack J8 with full volume (0dB gain), ADAU1772 codec got reset (register value goes to Reset default value).
If we do above at somewhat less volume (-5dB gain), plug/unplug works fine (no codec reset).
Also, observed if 0x0043 (OP_STAGE_CTRL) value 0x0 "Line Output mode", it is able to drive 16 ohm or 32 ohm headset without any issue.
I was expecting to drive 16/32 ohm headset only in "Headphone Output mode" (i.e. 0x0043=0x30). Audio output with 16/32 ohm headset has no difference/effect of 0x0043 = 0x0 (line out) or 0x30 (Headphone out).
Attached is our board schematic for reference.