Slicer settings different for one user than everyone else

Im a bit stumped on this one.

i have a report that has been published to Power bi service and is in a workspace with 5 members.

in this Report there is a slicer for MONTH as shown below

as you can see when logged in as my user the slicer allows for mulitple selection and shows a select all.

My issue is that one of my users when logged in is given radial buttons and can only select one month. (his versions below)

i have tried to republish the report from the desktop app ensuring that the slection controls are set correctly but this did not work.

i have tried to edit the report from within services and save but this had no effect 

i have tried editing the report from the users own machine (both desktop and service) but again is when opening the report the user is alwasy given the radial buttons 

i then tried to clear all his internent and browser data but again no effect 

i even tried using an alternative browser and uninstalling the browser and re installing it all to no avial 

i have now run out of ideas on how to fix this so that he is able to select muliptle months as all 4 other users can.

Does anyone know if there is a setting i am missing or has anyone experianced this issue before