In doing a search I found there were two U-boats with the designation of U-106. The one the Dutch found from WWI and another one that had a successful career during WWII.
This particular 106 was an 093 type. The boat number was 106, not to be confused with the type.
7 Oct 1917 - Lost in a new minefield off Heligoland when homeward bound. 41 dead (all hands lost).