The 32-year-old returns to the Bundesliga side after making six appearances during a loan spell there in the second half of last season.
Graham Potter said: “Markus has trained exceptionally hard and been a pleasure to work with during my time here, but this move gives him a chance to play regularly.
“He will be returning to a team that he knows well, and it is a move that makes sense for all three parties.
“I would like to wish him all the very best for the future, in what is an exciting next stage of his career.”
Suttner arrived at Albion from FC Ingolstadt in July 2017, and went on to make 17 appearances during his debut season in England.
The Austrian played once for the Seagulls in 2018/19, after featuring in the Carabao Cup tie against Southampton in August, before joining Fortuna Dusseldorf on loan in January.