Sounds like you bought a round seat for an elongated toilet.

That's not the case. Both seat and toilet are elongated. I believe there is an adjustment plate that should have been lined up differently

Seats do not have "adjustment plates". They fit the holes in the bowl. You bought an incompatible seat.

Did you use their fitment guide to determine of the toilet is compatible with the bidet seat?

https://alphabidet.com/pages/toilet-fitment-guide

I appreciate everyone who took the time to comment, but it turns out my concerns were unfounded. The bidet CAN be adjusted within a certain range. What they call the "Catch Plate" used in installation has a channel rather than a small hole in which the Fastening Bolts fit through so the seat can be moved backward or forward to adjust. The fellow who installed it spent less than 10 minutes and now it fits perfectly. (And, I had contacted Alpha before its purchase to make sure it was compatible with the toilet I wanted - something I recommend for anyone before making this purchase.) They were very helpful and I absolutely love this bidet.

One thing I would add to anyone contemplating this combination - the bidet seat is thicker than the regular seat that comes with most toilets. I bought an extra high toilet - and sat on it to see if my feet would meet the ground - which they did with the regular seat. It's more of a stretch with the bidet seat in place. Not a problem now as long as I don't keep shrinking with age. LOL

Glad you got it worked out. I am pretty sure my feet would be dangling if I used that seat especially on an extra high toilet.

Thanks for updating- I’ll be installing a couple bidets and your experience is very helpful. I also appreciate the info on the extra high toilet. 😁😊