I need assistance from a Windows activation specialist.

Situation: I replaced the motherboard and CPU on my PC. After the upgrade, Windows 10 Pro lost its activation. The license is a digital license that was previously linked to my Microsoft account (before the hardware change, the Activation settings showed "Windows is activated with a digital license linked to your Microsoft account").

What I've already checked:

• On account.microsoft.com/devices, I see two device entries: the old one (previous motherboard) and the new one (current motherboard) — both are the same physical PC, just with upgraded hardware.
• There is no OEM key burned into the BIOS/UEFI (checked with wmic path softwarelicensingservice get OA3xOriginalProductKey — empty result), confirming this is a retail/System Builder license originally activated through my Microsoft account, not an OEM key tied to the motherboard by a PC manufacturer.
• When trying to reactivate via Settings → Activation → "I changed hardware on this device recently" while signed into my Microsoft account, I get error 0x803F7001.
• I also tried phone activation (Installation ID via slmgr.vbs /dti) through the official extension activation page and the automated chat, but both responded that the installation ID could not be verified.
• OS edition: Windows 10 Pro.

Request: Please have a licensing specialist manually verify my license and re-link the activation to my new hardware configuration under my Microsoft account.