Status pages can tell you if a site claims to be working properly, or if it has identified issues, when those issues started, specifics as to what issues are involved, and if any updates or information is available.

Amplify online curriculum and assessments.

Blackboard

Canvas (see Instructure)

Classlink provides single sign-on to web applications and instant access to files in the cloud.

Clever is a digital learning platform for K12 schools, providing single sign-on, messaging, analytics, and more.

Edgenuity (Compass Learning), is a standard-based online learning resource.

Google (classroom, Gmail, etc)

Instructure (Canvas, Elevate (Elevate K12, etc.), Impact, Learn Platform, Mastery (Mastery Connect, etc.))

Jamf - Jamf Pro is the enterprise mobility management (EMM) tool that empowers IT pros and end users with unified endpoint management (including software installation) for Apple devices.

Learnosity

Mastery Connect (see the Instructure and Learnosity status pages)

NWEA (MAP), Northwest Evaluation Association (Measures of Academic Progress) evaluating K–12 math, reading, language usage, and science.

OKTA Used by Hough Mifflin Harcourt's i-Ready program.

Zoom video conferencing

Other Pages Than These

This isn't a list of every page on the Internet, nor even all the pages you might want. You can search the Internet for a status page for [whatever].com, or you can try downdetector's site, which allows users to report issues with websites.