Older models of iPad, including early generations of iPad Pro, lack the CPU/GPU and system resources (RAM) of newer models of iPad - and cannot be reasonably expected to provide the same levels of performance as may be found with much newer devices.
As with all operating systems, each major iteration of the OS will inevitably make greater demands of the host system hardware - and overall system performance may be negatively impacted. Your second generation iPad Pro, released in 2017, is already a five year old platform - with an A10X CPU and only 4GB RAM. More recent models of iPad have considerably more powerful and capable CPU - and benefit from significantly more system resources. By example, current models of iPad Pro have either 8GB or 16GB RAM.
Given your description of general system instability, your first step would be to perform a forced-restart of your iPad - as this will often clear an isolated or latent software issue associated with a recent system software update:
Force restart iPad (models with Face ID or with Touch ID in the top button)
If your iPad doesn’t have the Home button, do the following:
- Press and quickly release the volume button nearest to the top button.
- Press and quickly release the volume button farthest from the top button.
- Press and hold the top button.
- When the Apple logo appears, release the top button.
Force restart iPad (models with the Home button)
Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
If problems persist, you might be well advised to ensure that you have a current iCloud or iTunes backup - and then perform a full reset of the iPad. After reset, you should set-up again from scratch. After performing initial setup, you can then restore your data and settings from your backup.
To reset your iPad:
Settings > General > Transfer or Reset iPad > Erase All Content and Settings
This support page outlines restoring your iPad from your backup:
Restore all content to iPad from a backup - Apple Support