I thought I was the only one having this issue (Verizon also had me thinking this). But I just found this forum and just found a post that perfectly outlines everything I've been through.
(https://community.verizon.com/t5/Google/Pixel-6-Unable-to-Recieve-SMS-amp-MMS-Messages/td-p/1265623)
I'm still having the issue, had to contact them 2 days ago to have them remove all of the features from my account, re-add them and reset my Verizon network connections just to temporarily get my texts to work properly for the next few weeks and even that didn't work as well as it has previously because I continued to receive nearly 100 duplicate texts in the meantime.
I currently have my ~15th ticket open with Verizon which I assume will be closed soon with no resolution just like all of the previous ones.
Anyone have a permanent solution? Any Verizon folks on here that can help? I'm at my wits-end and ready to leave Verizon after nearly 20 years ...