Thanks Ben, may be i did clarify properly in my post - I am connected to computer via bluetooth and companion app but since both issues could not be sorted i tried using android app to troubleshoot and still facing the issue. So my primary mode of using Zwift is the computer.
I did read that spindown Bluetooth FTMS is enabled for Minoura Kagura - Game Update - March 27, 2020 - #5 by Paul_Allen?
Apparently the app that is mentioned by DCrainmaker does not exist anymore in Play Store so that’s a dead end but as an alternative I can do the spindown using apps of other manufacturers such as Wahoo Fitness.
The trainer is connected both as power and controllable and there is no connection dropouts during the ride. Un-paired and re-paired but still no luck with the resistance.