One more question.. is it possible to reduce the features like le security, or decrease supported bt version from 4.2 to something like 4.1. We have to use the pin based authentication and that seems to always come with full le security and encryption. We would like to test if decreased security, or none (we dont do any security sensitive stuff) would work better.
You can adjust the BLE security settings under the BLE component to choose lower security settings. The least-secure option is "No Security (No Encryption, No Authentication)"
That should help for testing purposes :)
(Under BLE component, GAP Settings tab, "Security" from tree)