In my grafana panels, new or existing, the expression feature seems to be broken.
If I click the +expression button it adds it but there is no space to type in the expression? No GUI to configure, no space to type in the expression.
Is it a bug? Or has the way you do expressions changed?
I suggest you give some more useful information such as your platform, your Grafana version, your browser & version (have you tried another browser?).
Have you tried disabling any browser ad-blocker or add-ons?
expressions are broken in version 9.3.6, scheduled to be fixed in 9.3.7 release, Beta is available now, not sure when alpha release.