Alternative to LEGO CONTROL+ app
There is an alternative app called BrickController 2. It is available for both Android as well as iOS. This application is actively developed and its maintainer can be reached on Eurobricks forums. You can also report and discuss any issues there. 

The application is universal compared with solution offered by LEGO since one device allows you to control more than just LEGO Power-UP electronics. The following receivers are supported, by the time of this answer:


LEGO Powered-Up HUB
LEGO Boost HUB
LEGO Technic HUB
LEGO Power Function infrared receiver (on devices having infrared emitter)
SBrick and SBrick Plus (3rd party devices)
BuWizz 1 and 2 (3rd party devices)