Handoff annoyance

I have 2 iPhones with 2 different phone numbers. One for my work, and one for my private life.

I have turned off the Handoff feature on both phones, but it is not working. From time to time I get the last calls history from one phone to the other.

because of this annoyance I tried the following:

I switch on Handoff on both phones.

Leave it on for 1/2 hour then switch it back off.

it works for a few days then it starts again sending my last calls list to the wrong phone.

I think this mostly happens when I switch WIFI off in one phone for a while, then turn it back on again. But I am not sure.

is someone else experience this handoff annoyance?

I know it is a feature that many people like but for me it is an annoyance. Since I have to keep my work phone clean I keep on spending a lot of time deleting unwanted entries in my call history.