How to send commands to manny switches in UI7

In UI5 i used this code
luup.call_action(“urn:upnp-org:serviceId:SwitchPower1”,“SetTarget”,{ newTargetValue=“0” },swi1)
it worked perfect in all ways.

In UI7 it is working in the same way, but not for a long time. if there are more than 3 switch, after a time it will come
error in lua for scenes and events

On my new project I have to control 7 switch, the error comes instandly or need only a few minutes to apear.

My conclusio is that it is to fast for UI7.

My Solution: put a
luup.sleep(900)
after every call action Line ;D

Have anyone some sugestions for this issue?

Thanks for your replies.

Franz