I'm experiencing intermittent connection drops where my devices (phones, laptops, etc.) suddenly lose Wi-Fi and fallback to the 2.4GHz band, resulting in very low speeds and poor performance.

Network Setup:

• Main Router: TP-Link Archer AX55
• Satellites: 1x Archer AX55 + 1x Archer AX12
• Configured as an EasyMesh network for whole-home coverage.
• Firmware: AX55 1.4.1 Build 20250821 rel.70686(4555) - AX12  1.2.1 Build 20250729 Rel. 73566

Symptoms:

• Devices refuse to connect to the 5GHz band when set to 160MHz channel width, causing drops and forcing re connection on 2.4GHz (with bandwidth capped at ~20-30Mbps).
• Signal strength and coverage appear fine; no physical obstructions or interference noted.
• This started after updating to the latest firmware—everything worked flawlessly before.

Troubleshooting Tried:

• Restarted all devices and routers multiple times.
• Reduced 5GHz channel width to 80MHz: Issue resolves immediately, and full speeds (up to 500+Mbps) are restored.
• Checked for channel interference using Wi-Fi analyzer apps—no obvious problems.
• Verified EasyMesh sync and backhaul (using wired where possible).
• Tested with a single device: Same behavior.

Expected Help: Has anyone else seen this with recent AX55/AX12 firmware? Any beta firmwares, settings tweaks (e.g., DFS channels, beam forming), or hardware workarounds? TP-Link support, please advise on a fix or rollback option.