$ for item in `cat german.list`; do echo -e "$item: "; echo -n "$item" | xxd -p; done
Ä: c384
ä: c3a4
É: c389
é: c3a9
Ö: c396
ö: c3b6
Ü: c39c
ü: c3bc
ß: c39f

$ echo -n 'schön5' >german.plain

$ cat german.plain | xxd -p
736368c3b66e35

$ cat german.plain | md5sum | awk '{print $1}' | tee german.hash
bbf9ee923fe21c044838865c7acf530d

$ ./hashcat -m 0 -a 3 --hex-charset -1 c3 -2 8489969c9fa4a9b6bc german.hash ?a?a?a?1?2?a?a
hashcat (v3.40-73-g99fbaa8) starting...

OpenCL Platform #1: NVIDIA Corporation
======================================
* Device #1: GeForce GTX 1080, 2028/8113 MB allocatable, 20MCU
* Device #2: GeForce GTX 1080, 2028/8114 MB allocatable, 20MCU
* Device #3: GeForce GTX 970, 1009/4037 MB allocatable, 13MCU
* Device #4: GeForce GTX 970, 1009/4037 MB allocatable, 13MCU
* Device #5: GeForce GTX 970, 1009/4037 MB allocatable, 13MCU
* Device #6: GeForce GTX 970, 1009/4037 MB allocatable, 13MCU

Hashes: 1 digests; 1 unique digests, 1 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates

Applicable Optimizers:
* Zero-Byte
* Precompute-Init
* Precompute-Merkle-Demgard
* Meet-In-The-Middle
* Early-Skip
* Not-Salted
* Not-Iterated
* Single-Hash
* Single-Salt
* Brute-Force
* Raw-Hash

Watchdog: Temperature abort trigger set to 90c
Watchdog: Temperature retain trigger disabled

The wordlist or mask you are using is too small.
Therefore, hashcat is unable to utilize the full parallelization power of your device(s).
The cracking speed will drop.
Workaround: https://hashcat.net/wiki/doku.php?id=frequently_asked_questions#how_to_create_more_work_for_full_speed

INFO: approaching final keyspace, workload adjusted

bbf9ee923fe21c044838865c7acf530d:schön5

Session..........: hashtest
Status...........: Cracked
Hash.Type........: MD5
Hash.Target......: bbf9ee923fe21c044838865c7acf530d
Time.Started.....: Sun Mar 26 08:46:08 2017 (0 secs)
Time.Estimated...: Sun Mar 26 08:46:08 2017 (0 secs)
Guess.Mask.......: ?a?a?a?1?2?a?a [7]
Guess.Charset....: -1 c3, -2 8489969c9fa4a9b6bc, -3 Undefined, -4 Undefined
Guess.Queue......: 1/1 (100.00%)
Speed.Dev.#1.....:  9411.3 MH/s (0.18ms)
Speed.Dev.#2.....:  9896.7 MH/s (0.18ms)
Speed.Dev.#3.....:  4829.7 MH/s (0.27ms)
Speed.Dev.#4.....:  5154.5 MH/s (0.27ms)
Speed.Dev.#5.....:  4555.7 MH/s (0.27ms)
Speed.Dev.#6.....:  4747.7 MH/s (0.27ms)
Speed.Dev.#*.....: 38595.5 MH/s
Recovered........: 1/1 (100.00%) Digests, 1/1 (100.00%) Salts
Progress.........: 902162052/69640284375 (1.30%)
Rejected.........: 0/902162052 (0.00%)
Restore.Point....: 0/81225 (0.00%)
Candidates.#1....: "yaÄ 1 -> }baü]a
Candidates.#2....: w!cÜ'p -> JWAÖe&
Candidates.#3....: {kaÄ^) -> psaÖ'p
Candidates.#4....: FUSÜe& -> Q!cä.+
Candidates.#5....: @loé.+ -> &11üV<
Candidates.#6....: /11ÄW~ -> :enü~}
HWMon.Dev.#1.....: Temp: 51c Fan: 34% Util: 63% Core:1898MHz Mem:4513MHz Bus:8
HWMon.Dev.#2.....: Temp: 49c Fan: 32% Util: 50% Core:1860MHz Mem:4513MHz Bus:4
HWMon.Dev.#3.....: Temp: 63c Fan:  3% Util: 96% Core:1354MHz Mem:3004MHz Bus:16
HWMon.Dev.#4.....: Temp: 62c Fan:  1% Util:100% Core:1366MHz Mem:3004MHz Bus:4
HWMon.Dev.#5.....: Temp: 65c Fan:  2% Util:100% Core:1379MHz Mem:3004MHz Bus:1
HWMon.Dev.#6.....: Temp: 66c Fan:  3% Util: 97% Core:1366MHz Mem:3004MHz Bus:1

Started: Sun Mar 26 08:45:52 2017
Stopped: Sun Mar 26 08:46:10 2017

$ cat utf8.hcmask.6char
?a?a?a?a?a?1?2
?a?a?a?a?1?2?a
?a?a?a?a?1?2?1?2
?a?a?a?1?2?a?a
?a?a?a?1?2?a?1?2
?a?a?a?1?2?1?2?a
?a?a?a?1?2?1?2?1?2
?a?a?1?2?a?a?a
?a?a?1?2?a?a?1?2
?a?a?1?2?a?1?2?a
?a?a?1?2?a?1?2?1?2
?a?a?1?2?1?2?a?a
?a?a?1?2?1?2?a?1?2
?a?a?1?2?1?2?1?2?a
?a?a?1?2?1?2?1?2?1?2
?a?1?2?a?a?a?a
?a?1?2?a?a?a?1?2
?a?1?2?a?a?1?2?a
?a?1?2?a?a?1?2?1?2
?a?1?2?a?1?2?a?a
?a?1?2?a?1?2?a?1?2
?a?1?2?a?1?2?1?2?a
?a?1?2?a?1?2?1?2?1?2
?a?1?2?1?2?a?a?a
?a?1?2?1?2?a?a?1?2
?a?1?2?1?2?a?1?2?a
?a?1?2?1?2?a?1?2?1?2
?a?1?2?1?2?1?2?a?a
?a?1?2?1?2?1?2?a?1?2
?a?1?2?1?2?1?2?1?2?a
?a?1?2?1?2?1?2?1?2?1?2
?1?2?a?a?a?a?a
?1?2?a?a?a?a?1?2
?1?2?a?a?a?1?2?a
?1?2?a?a?a?1?2?1?2
?1?2?a?a?1?2?a?a
?1?2?a?a?1?2?a?1?2
?1?2?a?a?1?2?1?2?a
?1?2?a?a?1?2?1?2?1?2
?1?2?a?1?2?a?a?a
?1?2?a?1?2?a?a?1?2
?1?2?a?1?2?a?1?2?a
?1?2?a?1?2?a?1?2?1?2
?1?2?a?1?2?1?2?a?a
?1?2?a?1?2?1?2?a?1?2
?1?2?a?1?2?1?2?1?2?a
?1?2?a?1?2?1?2?1?2?1?2
?1?2?1?2?a?a?a?a
?1?2?1?2?a?a?a?1?2
?1?2?1?2?a?a?1?2?a
?1?2?1?2?a?a?1?2?1?2
?1?2?1?2?a?1?2?a?a
?1?2?1?2?a?1?2?a?1?2
?1?2?1?2?a?1?2?1?2?a
?1?2?1?2?a?1?2?1?2?1?2
?1?2?1?2?1?2?a?a?a
?1?2?1?2?1?2?a?a?1?2
?1?2?1?2?1?2?a?1?2?a
?1?2?1?2?1?2?a?1?2?1?2
?1?2?1?2?1?2?1?2?a?a
?1?2?1?2?1?2?1?2?a?1?2
?1?2?1?2?1?2?1?2?1?2?a
?1?2?1?2?1?2?1?2?1?2?1?2