I have had that happen several times when the call is coming from mobile network to landline or vice versa.
Two instances, my sister on Vodafone network phoned on the landline and the CLI that came up was not her’s. I telephoned the CLI number that came up and the the user (a man answered) was shocked to find his number being used. He was also located in different part of country. However, the part of the country this man was located was fairly close to where my sister was located.
The second was a landline CLI that kept ringing my mobile. Eventually I rang the landline CLI and a woman answered phone. I informed her her number was ringing my mobile. She became worried as she said she had been away for several days and had onoy been back 30-minutes before my call to her landline. Spooky.
Point of interest the part of the country she was located I had been in that area some two days before folowing christmas holiday.