A lot of church bells these days are not real bells, they are PA systems playing a recording of church bells. They are often programmable and wirelessly contro

A lot of church bells these days are not real bells, they are PA systems playing a recording of church bells. They are often programmable and wirelessly controlled, for example: https://www.brgproducts.com/carillon_pricing/index.php https://www.brgproducts.com/carillon_pricing/index.php So it seems entirely possible the wireless part of the church bell system was interfering with your router. If the church did have real bells it seems very unlikely they would generate strong EM radiation at 2.4GHz or 5GHz. They might induce some vibration if they are really loud, which could trigger an intermittent connection in the router, though that seems pretty far fetched also.