What version is this on? I remember an issue in the past where a bunch of UDT parameters were changed to string type. It may or may not be related to what you are seeing as I was not using the multi-instance wizard. I haven't run into that issue on more recent 8.1.x versions.
Sorry for digging up an old topic.
I'm working with version 8.1.35 and I encountered the problem described above.
All parameters given a value in the Wizard change their type to string.
Any ideas how to solve this?
Unfortunately, there is no solution with the wizard. Most people simply write a script that builds a list of tag definition dictionaries for system.tag.configure.
Actually, I just remembered that system.tag.configure also converts UDT parameters to strings. Where I've done this, I've used system.tag.configure to do everything except the parameters, followed by system.tag.writeBlocking to supply those.
In parallel, I corresponded with Support IA, who analyzed the operation of the Multi-instance Wizard.
It turned out that the problem I encountered in version 8.1.35 was solved in version 8.1.41 and later.
In the current version 8.1.42, parameter types do not change when creating an instance using the Multi-instance Wizard.