Does call waiting work on vodafone?

[Things change I've changed]

Both me and my GF have moved onto Vodafone basic sim only contract recently, I have a Mate 20 x, she has a Samsung s20, both have call waiting enabled in the settings but when, I've tried speaking to vodfone chat and they just send me round in circles keep linking me to a guide for our phones which we have both followed, this feature particularly for me is essential to me job, previously on giffgaff this feature worked fine!

 

[ttaskmaster]

Worked fine on all the phones I've ever had, including the S21 Ultra.
Why not test it - You phone a mate, then have GF call you, see what happens.....

 

[Things change I've changed]

I have tested similarly as you've suggested, just goes straight to answer phone.