@ jelv:
Never did have the phone's MAC address listed in the reserved IP listing only on the Wi-Fi fitered access listing, that was one of the first things I thought of, ie., might have inadvertently included the phones MAC in the reserved IP listing, was not the case.
Yes, I had thought of doing a back to factory settings reset and re-configure, I have stored the final configuration to ROM D so should not be to difficult, although, that will likely restore any fault also, may need to manually re-configure.
However, with just changing to a "one box" setup yesterday and instigated a number of un-necessary re-synch's until I figured out that the DSL LED being steady amber meant VDSL synch OK (finally read the manual), don't wish to mess things about for a day or two less I evoke the wrath of the dreaded DLM..