I have a 2015 Honda odyssey that when you press on the gas you get a shuddering feeling. It shifts alright but even at highway speed if you accelerate you get the shudder. Is this a transmission problem or something else?

 

Apologies if this response to your question seems trite... Suspect your tires before you suspect your transmission.

Do the easy stuff first. Rotate your wheels and go for a highway test drive. Note the speed or range of speed the vibration occurs. If the vibration persists after wheel rotation, go to your preferred shop and explain you're hunting the source of vibration at highway speeds. They should know exactly what to do, but have them inspect each tire for imperfections (flat spot, bulge, mount issue, sidewall issue), check balance a/o remount each tire, and get an alignment. If the vibration persists, the list of things to investigate is relatively short, and ends with the transmission.

 

Hondas don’t break, keep driving.

 

When is the last time you did a 3 qt oil change on your transmission.
I do it every 3rd motor oil change.