iPhone tone to not working to open our community gate
Our community has a call-box at the gate that allows visitors to contact the person they are visiting to be allowed in. Owners in the community press the “9” key to activate the gate opening. For the past several months (nearly a year, possibly?) this is not working for several of our Owners. The gate people say it has to do with Apple lowering the volume of the tone sent from the iPhones. The iPhones vary from the iPhone 8 to more current phones.
Can someone tell me 1) if this is true, and 2) how it it can be corrected?
iPhone 8 Plus