Follow up on this thread. It has been resolved. Here is Mike’s post from a different thread:
We have resolved this bug. It was caused by low-level Bluetooth protocol change in newer iPhones. Android phones and iPhone 7 or earlier phones are not affected. Only IM100 meters shipped before Jan 1, 2018 will have a problem.
Please contact us if your meter was shipped before Jan 1, 2018 and you can’t connect to your iPhone 8 or X. The issue can be resolved with a meter firmware update. You can update the firmware yourself if you have access to an Android or older iPhone, but the process is fairly technical. Or, if you prefer, you can ship your meter back to us and we will update the firmware for you. Most meters are updated and shipped out the same day they’re received.