intermittent outbound call failure (rejection?) from call URI

The current app store version of linphone. Outbound calls from URI fail intermittently. Steps to reproduce

install from app store
call linphone with full sip://[number]@[ipaddress] URI from safari or other app
end call
swap back to app and repeat

Intermittently, linphone just stops at dialpad, but doesnt seem to initate call. Error message from device logs below.

Seems random, regardless of:

power state ( charging|unplugged)
reg state ( registered sip acount | no sip account )
sleep mode ( locked|backgrounded for a while or right away)* I do have to backgound linphone to jump to other app, but it's in background for less than 2 seconds
interval - doesnt seem to matter if linphone in in background less than couple seconds or several minutes

default callservicesd 17:48:44.021384-0600 Validating intent for call source: <private> callSourceHasReasonableUserIntent: <private> isUserIntentConfident: <private> (<private>) default callservicesd 17:48:44.021449-0600 [WARN] Not allowing requested CXStartCallAction because user intent could not be validated for call source with identifier: <private> error callservicesd 17:48:44.021509-0600 SimulateCrash() on another process is not supported ...

default callservicesd 17:48:44.024409-0600 [WARN] Not allowing requested transaction: <private> default linphone 17:48:44.025057-0600 Received reply from transaction request with error: Error Domain=com.apple.CallKit.error.requesttransaction Code=6 default locationd 17:48:44.031704-0600 Received state update for 2523 Tried to lookup error message but can't find decent explanation. Seems like framework is randomly rejecting the call request. I don't understand what is not validated, or why it would intermitently reject with same number@ip, same method, same settings back to back with a successful one.

BelledonneCommunications / linphone-iphone

intermittent outbound call failure (rejection?) from call URI #831