OBB doesn't allow seat selection anymore?

I think your problem stems from buying the tickets on DB . I purchased RJX tickets ( Munich to Vienna )about three weeks ago , but bought them on Austrian State Railways . No difficulty buying two seat reservations with the transaction . . OBB is the operator of the train , not DB .. Also , if buying from DB you could have done that with a Bayern ticket - about 45 Euro for two people .Any change in your ticketing would depend on the grade of ticket you purchased

Reservations and tickets are separate. You don't need a ticket to make a reservation. You can buy a ticket from DB and a reservation from ÖBB and vv.

A few more remarks:
- This is a DB train. It only becomes an ÖBB train after Salzburg.
- When you reserve seats for multiple persons the system will try to seat you together. If that is not possible selecting seats on a seat map won't help either.
- Reservations are not compulsory...
- You can't change reservations. You are free to sit somewhere else though.

Don't overthink this. This is mass transit.

Thank you both for replying. I read a lot of information before buying my tickets. I chose first class for a little more comfort and legroom, and could only get sparpreis prices from DB. The train is listed as RJX 67, so should be one of the newer (red) OBB trains?
As I noted, up until today I was able to see the seat maps and pick my seats, but could not reach the check out page. Now there’s no option to view the map and takes me directly to checkout.
I suppose worse things can happen. At least we will have reserved seats…. 😬

I notice recently that a saved link to the ÖBB "scotty" schedule information page was suggesting I should use the updated version, which looks much smarter but (obviously) doesn't offer all the original options up front! This is called progress....

Yes RJX67 is a dark red Railjet (unless it's covered in advertising vinyls!!) , but of the original design - which is not a bad thing....

The trains starts at Munich and goes to Budapest, it is planned for track 8 at Munich Hbf but geography restricts it to the group 5-10 so it can't vary much. So if you get there say 15 minutes before departure you'll have choice of unassigned seats, always worth reading the details of those that are reserved since it is first stop Salzburg, so anything showing reserved from anywhere other than Munich will be free for your journey. And if a seat is reserved from Munich and nobody has claimed it within 10 minutes they probaby missed the train! First class is at the front, car 26 is entirely first class, car 25 has a few first class seats next to the restaurant. The front (car 27) has clear labelling for Premium/Business Class but has a batch of First class at the end connected to car 26.

Bayern Ticket would not have been suitable for this journey because they are not valid in RJX trains.

" Bayern Ticket would not have been suitable for this journey because they are not valid in RJX trains." Obviously , but you can make that trip easily on regional trains which are covered by Bayern ticket

Could be worse: https://youtube.com/shorts/ec3Nd0wvzME?si=nyV_Uhd3KZenNb46

@James , really good point ;-)

there a problem with that video of the ÖBB train - it's clearly not an ÖBB train!! The CD Restaurant is a bit of a giveaway it's a CD Railjet. I also have real doubts about the open space with opening window and cheap flooring, that looks like a different type of CD train. But I've just tried to buy a ticket from ÖBB more than 180 days out and they won't let me - so what did these people do?

The OBB time frame is 180 days out , sooner than that you have to wait The RJX 69 tickets for my trip ( Munich - Vienna ) were purchased , with reservations , on 4/24/26 for travel on 10/21/26

But I've just tried to buy a ticket from ÖBB more than 180 days out and they won't let me - so what did these people do?

Nothing out of the ordinary. That's their standard advance booking period. The one-year advance booking period applies only to DB, but it has little practical significance.

To confirm the sale date , go into Bahn ( The DB site ) and fill in the information for your trip . When you reach the end and hit search , the potential trains will be listed , and the last column will indicate the pending date sale of the ticket begins . Buy the ticket on OBB

I suppose it's better to have guaranteed seating in case we're slow to board. At least, the OBB website indicates this train falls within the "peak travel" period.
We can always switch seats if better (unreserved options become available). I didn't realize that Salzburg would be the first stop on this train, so that makes it much easier.
Thanks for the track info and timing advice, @me.crewe!

Fritz, so are we saying that the Youtubers bought their tickets too early from DB or another 3rd party, which would also mean they wouldn't get to choose the cheaper Sparschiene prices, travelled on a CD train and then made a video blaming ÖBB? And other people are supposed to take their advice?

That youtube video confirms that a lot of problems non Europeans encounter with train travel are due to booking to early...