Getting issue after enabling
form_key from backend.
When I am trying to open
store > configuration
from Order section it took me redirect to admin dashboard
Hi I cannot "add a comment" yet, so this is the only place I can write.
I also see this issue having performed an upgrade to 2.2.8 from 2.2.2 today, however I am being redirected to the Orders screen rather than Dashboard, and from a variety of places (including attempting store > configuration as you did, and in fact attempting to see Dashboard sends me to orders...) - it'd be interesting to know if you get the redirect from other places too (e.g. Indexer or Cache screens, where I also suffer the issue).
I have also been battling with serialization / deserialization issues as a result of the same upgrade, and wonder if there is some serialized (old style pre-Json) data in your core_config_data table somewhere that might be throwing it.
Take a look at - https://github.com/magento/magento2/issues/22366 Body must be at least 30 characters.