My mom has a LG V30. Starting last weekend she noticed when she calls some landlines she just gets a busy signal. She is not using wifi calling or calling plus or anything nifty. She does have a blocked number – but we know that only one of the landlines she’s calling does actually block unknown numbers (previously dialing *82 and then the number worked for her with this landline). She’s been to a store to try and get assistance—they did a reset, changed sims, etc. But still no resolution. Any ideas on what could be going on here?