Who I have the same questioned this topic

I have LTE home internet, using the Askey ASK-NCQ1338 modem.  Before switching to Verizon, I used cleanbrowsing.org's DNS content filters for our family.  The DNS addresses are entered into my personal router connected to Verizon's modem (it does not appear there is a way to change the DNS settings in the Verizon modem itself).  The rest of the devices are connected through my router for both WiFi and LAN.  For a few months this seemed to work with Verizon.  I could go to dnsleaktest.com and the test results would show cleanbrowsing.org.  Lately, the filter is not working, and dnsleaktest results show myvzw.com as the DNS hostname.  It appears to me that Verizon is redirecting my DNS requests to its own DNS servers.  I have not changed my configuration.

Does anyone know a workaround for this?  I called tech support and the agent was not able to help.

I'd really like to have the adult filter working.  Verizon doesn't offer any comparable service for filtering, at least at a network-wide level.  I like the service and price, but it will probably be a deal breaker for me as soon as there is another ISP available in my area.

Thank you.