This behaviour that you describe - with the on-screen keyboard remaining on the screen for a few seconds - is a bug in iPadOS 27/27.0.1. A forced-restart will not clear this issue.
You and anyone else that encounters this issue would be best advised to submit a Bug Report via Apple's Product Feedback portal:
Feedback - Apple
When submitting your Bug Report, please ensure that you include details of your device model and installed OS versions within the body-text of your report along with details of the problem. Do not rely upon the pick-list alone - as this often fails to include the most recent OS versions.
Every Bug Report counts. Unless sufficient reports are submitted (with adequate detail), Apple may not assign resources to investigate and correct the issue.
In addition [i.e., not as a substitute] to submitting a Bug Report, you might also consider seeking assistance directly from Apple Support. You can contact the Support Team using the Support link at top-right or bottom-left of this page; you can initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
You perhaps haven't yet noticed, but there's another similar issue with the Wallpaper image. When rotating the iPad between Landscape and Portrait screen orientation, or vice versa, rotation of the background Wallpaper similarly lags...