Sorry for the inconvenience
Unfortunately, Iris doesn't function well on iOS 12 and above due to the Apple terms and conditions so that might be what's causing the issue
I would recommend referring to our page on how to install iOS and troubleshoot Cydia:
We're still trying to work out a solution for better experience and will contact you as soon as possible
Again sorry for the inconvenience and thank you for supporting Iris
Customer Communications Manager and Lead Marketing Specialist
Iris Technologies Ltd.