turn off only works on second attemp if it was turned on a second before
with the beta.5 update if you change the state of a device for example a dimmer to let's say on then off within a second it does not react you have to wait few more second's thenn turn it off again, thenn it works

a bit hard to explain if you hit klicking on a device on ios home app it react's only to the second klick while turning it off shortly afterwards you had turned it on, if you wait a bit it turns of instantly - might be a state that's not updated fast enough.