Not all issues are caused by VPN usage.
Unpredictable stalling of an App, followed by the App terminating, is often an indication of resource exhaustion. While iPadOS is supposed to effectively manage its system resources, iPadOS 17.x appears to have a bug with its memory management.
While it should be unnecessary to manually close Apps unless an App is misbehaving, when system performance becomes noticeably sluggish (this often being a precursor to an unexpected crash), it is often beneficial to manually close Apps that are not being actively used.
In more detail...
By design, it should not be necessary to manually close any open Apps. iOS/iPadOS should transparently and seamlessly manage its available resources as you switch between Apps and tasks. This mechanism appears to be broken, or at least significantly impaired, in all production versions of iPadOS 17 released to date.
While your iPad should be able to switch between Apps without issue, paging Apps and data between available RAM and local storage when memory is required for other tasks, this mechanism appears to be at best unreliable in iPadOS 17. As such, unsaved data may be unexpectedly lost and/or an App may unexpectedly quit and have to be re-initialised when switching between tasks.
Until this issue is resolved, as a workaround, you may find that manually force-closing Apps that you are not currently using will provide some relief. You can force-close Apps from the App Switcher page...
To expose the App Switcher page, swipe-upwards from the bottom edge to the centre of the screen, pausing briefly before lifting your finger from the screen; you will see a thumbnail image for each of your currently open Apps. Apps can be force-closed by swiping the corresponding thumbnail off the top of the screen.
You would be best advised to submit a Bug Report, linking to this thread, via Apple's Product Feedback portal. For iPad and iPadOS:
Feedback - iPad - Apple
When submitting your Bug Report, please ensure that you include details of your iPad model and installed version of iPadOS within the body-text of your report along with details of the problem. Do not rely upon the pick-list - as this rarely includes the current version of iPadOS.
The link to this thread is - https://discussions.apple.com/thread/255213669
Every Bug Report counts. Unless 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
