Full fare ticket are fully flexible that day. Just get on the next train. For SparPreis ("saving fare") tickets, for connections entirely in Germany (all Bahn), and I assume for connections between the Bahn and ÖBB, if you miss a connection due to the fault of the railroad(s), just go to the ticket counter and they will change your ticket to the next train. If it is your fault that you missed the connection, sorry.
It looks like you are looking at SparPreis fares. When they start selling these tickets, they start with the lowest price and, as the lowest priced tickets sell out, the price goes up. Munich to Vienna is a popular connection, and it looks like the lowest priced tickets with a better connection times are sold out (it's less than a month in advance).
You might try going via Regensburg. Put in Passau as a stopover. That will force a route through Passau, but you won't necessarily change trains there.). That uses a regional train from Munich to Regensburg where you catch a RailJet or ICE to Vienna. It takes a little longer, but not much. You might find better fares there. It looks like the connection time in Regensburg is 12 minutes.
Or, look for fares from Salzburg to Vienna on Westbahn. Book Salzburg to Vienna on Westbahn and take a Meridian regional train to Salzburg using a 31€ (for 2) Bayern-Ticket.
One more hint, instead of "adjusting" the connection time after pulling up the schedules, put in Salzburg as the intermediate stopover on the original query (Use "Change other data") and specify a longer stopover time, say 00:30 (thirty minutes). You might get better fares that way. Your change time that way will probably be longer than 30 minutes, but no less.