Maybe it is only possible for trips Germany-Italy?

I would understand that it is valid on DB-ÖBB Eurocity trains only (in Austria and Italy), what is the case here. 

Maybe we can get some official information from Eurail

@Annie. 

I've tried a lot of options -- munich to innsbruck (which would be a pain to have to go back, but regardless). Innsbruck to Bolzano. Not a single train is valid regardless if it's EC or RE. There's no DB or OBB trains. If it's a conditional, near impossible route, why would Eurail advertise it? What a waste. Have to cancel my hotel in Bolzano .

https://www.interrail.eu/en/interrail-passes/german-rail-pass

The trains that are included are detailed at the bottom of the page - expand the section.

If the train is a DB-OBB EC train then you can always add the train manually to your pass. I believe they all depart from Munich and through the Brenner Pass to Verona.

No, DB-ÖBB trains are the ECB trains Munich-Innsbruck-Bolzano-Verona-Bologna/Venezia trains. could you try out to book Munich-Bolzano to see if this works?

RE trains are not included in your pass in Austria and Italy. 

You can also get in touch with customer service via https://eurail.zendesk.com/hc/en-001/requests/new, please write in your request when (date, hour, train) you will travel (asap or soon is not enough) to get prioritised. 

Manually will not work, because the starting station and ending station is in Austria and Italy. One possibility is to write Innsbruck (Germany) to Bolzano (Germany) so the app things you are in Germany, but would this be fine for the train staff?

I figured it out. It's a pain, but it recognizes a train from Munich OST (not Munich HBF) to Bolzano. So I have to go back to Munich HBF and then get to Ost and depart to Bolzano from there. A little bit convoluted and costs me a few extra hours of time. But at least it's possible!

Apologies - I forgot the B. Thanks for the correction.

The ECB trains are scheduled to depart from Munich Hbf before Munich Ost so simply get on there and add the short leg as a separate journey to your trip/pass.

You may find a 10 euro tariff will be added for this journey.

The trains run as Eurocity - EC but the Railplanner App says ECB (Eurocity Brenner). 

Due to works often the trains start in Munich East (München Ost) instead of Munich main station (München Hbf). 

The 10 Euro fee is only for Interrail/Eurail Global Pass and One Country Italy. With the Eurail/Interrail German Rail Pass you have not to pay the fee, because it is run by DB also in Italy. 

@Autumn Howard You could enter the train in Innsbruck checking in for Munich-Bolzano and ask the train staff before entering the train if it is ok, maybe also asking today for your next trip. And you don’t have to go to Munich, the first station in Germany is Rosenheim, you could there get in and out if needed. 

In Innsbruck Hbf there is a Eurail Aid Office in the ÖBB first class lounge to ask for help, maybe they can help or at the ÖBB Ticket Office. But I’am not sure how much they know about the Eurail German Rail Pass, because it is not valid on ÖBB trains, only on trains run in cooperation with DB - Deutsche Bahn. 

Innsbruck Hauptbahnhof: ÖBB lounge

Monday to Friday: 5:45am - 9:40pm

Saturday and Sunday: 6:15am - 9:40pm

You could also ask directly DB Italia:

Milano

DB Vertrieb GmbH Via Napo Torriani, 29 20124 Milano

Monday to Friday: 9:00am - 6:00pm

Phone: +39 02 6747 9578

E-mail: info@dbitalia.it

It should be possible to book a train from Munich Germany to Salzburg, Austria and to some cities in Italy.

Eurail German Rail Pass | Interrail.eu

@Annie. Sorry Annie. Did you read the question?

@Autumn Howard wants to go from Innsbruck to Bolzano with DB-ÖBB Eurocity Brenner. The app says not possible. Should this not work? Because Munich-Innsbruck is possible and also Munich-Bolzano (via Innsbruck)

@Angelo I did :) 

@Autumn Howard’s reply:  Munich OST (not Munich HBF) to Bolzano. So I have to go back to Munich HBF and then get to Ost and depart to Bolzano from there. A little bit convoluted and costs me a few extra hours of time. But at least it's possible!

Hi @Annie. :)

Sorry, but the question is to get from Innsbruck to Bolzano with an Eurail German Rail Pass.

The solution to get back to Munich (from Innsbruck) and then go Munich via Innsbruck to Bolzano is a bit strange? Or is it not possible due to some rules? Because from the eurail website it is not clear if it is possible or not.

Thanks

Tag also to @Camilo. @Nanja 

Currently checking with our Team.

May I suggest you contact DB direct and not your team? That will fasten things enormously.

At lest on old-style paper passes, still directly on sale by DB, this would be no problem at all.