A very common HP issue where the printer reads Offline in Windows/macOS or the HP Smart app despite being on. HP Smart's tools plus a few Windows settings usually fix it.
Work through these in order; most people are fixed by the first two or three.
Open HP Smart › select the printer › use "Printer Settings"/diagnostics to reconnect it. Reinstall HP Smart if it can't see the printer.
Open the print queue › Printer menu › clear "Use Printer Offline" and cancel stuck jobs.
Give the printer a static/reserved IP in your router, and untick SNMP Status in Printer Properties › Ports › Configure Port.
Restart printer, router and PC. If it persists, remove and re-add the printer (by IP if needed).
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