You're right. Both small locks are out of service since 2014 and have been filled with sand in 2018/2019. The plan is to rebuild them in the coming years.

As part of the newbuilt programm of the small Holtenau Locks the pits have been filled with 135.000 cubic meter of sand to stabilize the old lock walls. Ground survey is ongoing for possible war ammunition. Building start will be in 2023, completion around 2030. Once ready the main locks are next.
Rgds, Manfred

Nice ! Have those lock pits been filled in? I can't see it properly but it looks like they might be dysfunctional