The train is departing earlier than originally scheduled. Am I restricted to a specific train? Will my seats remain reserved?

Hello,

Unfortunately, Deutsche Bahn itself can't help me, or rather, their answers to my questions are vague and not clear enough. I booked an ICE train from Munich to Hanover with the Super Sparpreis ticket.

I have also reserved seats on the ICE because the train is expected to be very busy and I don't feel like traveling on the train for 6 hours with my suitcase.

Now, by chance (I didn't receive any notification or anything like that), I see in my booking that the booked connection is cancelled and I should look for another connection.

There's actually no longer a train connection, since my booked connection is canceled, right? Well, no sooner said than done. I looked for another connection, found one, and noticed, "Oh, man, that's the train I originally booked, only it now leaves Munich about 20 minutes earlier than originally planned."

So I'm assuming I can take this train (either way, since the train connection is no longer valid?) and am wondering if my seats are still valid. It's essentially the same train, it just leaves earlier (probably due to a schedule change).

I googled like crazy but didn't find anything that could give me a 100% answer as to whether my seats would stay.

So I contact Deutsche Bahn, who just keep telling me when my train connection will no longer apply and that there might be timetable changes due to construction work or something, and that I would have to reserve new seats on another train and have the original ones replaced.

Only in my case, it seems a bit more complicated, since it's the same train, just earlier, and you'd think that Deutsche Bahn should actually be able to keep the seats. They can't tell me that all passengers will have to rebook, can they? Can someone perhaps tell me something from experience? I'm grateful for anything I can learn.