I updated to IpadOS 17 recently yet have no stage manager at all

The tags appended to your post suggest that you have an iPad10. The iPad10 fundamentally does not support Stage Manager.

Due to limitations of internal hardware, Stage Manager (as introduced with iPadOS 16.1) is only available for these models of iPad:

• iPad Air (5th generation)
• iPad Pro 11-inch (all generations)
• iPad Pro 12.9-inch (3rd generation and later)

Feature availability is usually limited by system hardware - CPU and available RAM being critical to some advanced functionality.

iPad models supporting Stage Manager have an M2, M1 or A12X CPU (upon which the M-series CPUs are reportedly based) - with at least 8GB RAM.

You're very welcome. I'm sorry to have been the bearer of unexpected news.

Without Stage Manager, you will still have access to the established Full, Split and Slide-over multitasking views - accessible from the three-dot button.  When using the iPad without a connected external monitor, standard multitasking views are [arguably] far more useful.