HyperTunnels "Foundation 8x2 HT Vrt 1 Corner" has 4 holes, not 1.
HyperTunnels by @Roze Foundation 8x2 HT Vrt 1 Corner specifically seems to have the model with 4 holes instead of just 1. All other vertical holes though foundations appear correctly. Mod version: 1.0.7
Solution
Update pushed. Should fix the remaining offsets. Seems to have been introduced with the migration to instance based foundations.