This is because Pear studied some ways to better fit the adapter, with different inclinations and depths of the connectors.
The oblique connection is correct, but maybe your interface needs the connectors to be enlarged to reach deeper on the Enterprise sockets when cased. This has to be done with a soldering iron. I think that drawing them out 1mm will be enough, not needing to change the connectors.
Think that the adapters are hand made individually and can show some differences.
Also think that some Enterprises have a displacement of the main-board respect to the plastic holes of the case. I talk about it
hereMaybe you can try to align the connector's pins to the main-board fingers when plugging in.
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On the other hand, please, can you put some more pictures of the case?.
And, I own three EnterMice adapters(1 prototype and 2 from the second improved batch) and I am interested on some cases if they are available to sell....