Can you try to remove their record in "AR System User Preferences" form?
At least for one of them?
I don't quite understand as to what do you mean why you say, "remove their record in "AR System User Preferences" form"?
Would you be kind enough to elaborate?
Can you try checking the User form, and see if the correct GroupID for the company is added to their Group List ? I had a similar issue before where for some reason the groupID for the relevant company wasn't added to User form, even though it was visible in the CTM:People form.