If you add a Title Studio effect in Avid to filler on the track above another title studio effect, the effect on the lower layer takes all of the properties of the title studio effect on the upper layer. Steps to reproduce this.
Avid V1 create text with title studio.
Avid V2 drag new title studio effect to the empty track.
Immediately the text on V2 changes to whatever the text is on track 2. If you undo adding the 2nd title studio effect the v1 text reverts back to whatever was typed.
This is on a MAC Avid 2018.3 and BCC 11, I have another avid 8.8.5 running on Wiindows with BCC 10 and stacking the effects works fine.