When using Wireless Calling I find that there is frequent change from duplex to simplex conversation! I can hear the other party but they suddenly cannot hear me. I also find that sometimes there is no dial tone available when I attempt to call a known number - either mobile or fixed. I have an iPhone 11 and the ISP is TalkTalk.Today the conversation changed to one way four times in a single conversation and each time my contact had to initiate the call afresh.
HELP!