I came up recently with this. In Section Access, "*" doesn't mean "all possible values in field COMPANYNUMBER" but "all listed values in your section access under COMPANYNUMBER field". Even if the user has admin access won't see anything.
What you can do is create one entry for each possible value is has granted, or some dummy records in the section access which contain all possible values, taking into account that you can only set one value per record per user, meaning that if one user has access to two different companies, he will need two different entries in section access.
Apart from this, make sure you have
"STAR IS *;"
before the user records, so the * is read as "all listed values".
Hope that helps!