I would need a bit more info here.
Url to install?
Test login and does this happen with vb3 integration off?
I run 2.91 and vb3.07 and Vbportal 302 and I can post a manufacturers name no problem
The variable is named $manuf and I show it to be coded correctly and inserted into the database correctly
The only time I see issues with variables not being written is when using VB3 one has a hack installed that has a same name or interferes with our program operation. Hense why I asked if it works with vb3 integration off.