Sometimes, when using any device on iOS, you can face a problem where you are unable to connect to your app after using Legacy Bluetooth mode and then back to normal Bluetooth.

For starters, you should restart your phone (as in fully turn it off than on again) to clear your phone's cache, then you need to do the same on your device.

Here's the step-by-step guide on how to workaround this issue.

You can easily clear the cache by turning the device off and then on again using the power button on the top of your device.

If you look closely at the Handy 2 buttons, you should be able to see a indentation at the diagonals between each button.

For this next step, you'd need to use a paperclip (Or similar diameter tool) on the top left indentation.

Push your paperclip through this indentation, this will open a small hole in the silicone but is expected and won't void your warranty. This won't damage the Handy 2's capabilities of passing a IPx5 test as the silicone will close enough so no fluids will get to the PCB.

Once you press this button, the Micro Controller Unit will reset and this will clear the cache so you can use the Bluetooth mode.

Because the Oh! runs on batteries, turning the Oh! on and off won't do the trick, instead you need to let the device fully drain the battery as that will force the cache to be cleared.

You can turn the device's on to max intensity to quickly drain the battery or slowly drain it in low intensity.