I use #43# to turn off call waiting, it works perfectly during the day and evening but overnight at about 3 AM it seems to re activate by itself. I also turn it off via the toggle in Supplementary Services and the same issue happens. I am on the Vodafone network.
Any ideas on a permanent fix would be appreciated.
Not sure if you've seen it already, but I found this on the Vodafone forums: https://forum.vodafone.co.uk/t5/Archive/call-waiting/td-p/2478779. The original query and solution of that thread is the opposite of what you're after, but I'm wondering if adjusting your Call Forwarding settings might work in your case.
(For an A70, for example, it'd be Phone app > 3 dots (menu) > Settings > Supplementary Services > Call Forwarding > Voice Call, and disable/enable the options.)
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