These are carried on the same broadcast frequencies as the channels you mention and so would also be affected by a signal fault. If that confirms the symptoms, then first check whether VM have any reported faults in your area - by calling 0800 5610061
If nothing's listed, you need to report your fault. Call 150 from a VM phone, or 0345 4541111 from any other phone and follow the "I have a fault" options. The automated service may try to be helpful, sometimes by running some tests and offering an engineer (take it!!) or otherwise saying "please wait while I run some tests", and then you callback 10minutes later and speak to an agent.
VM should ultimately, either replace your box or arrange an engineer callout. Anything else is unlikely to solve this, but either of these could.
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