mt7922 / mt7921e: Frequent disconnects

I'm using a 7922 card, which loads the mt7921e driver, on a NixOS system:

01:00.0 Network controller [0280]: MEDIATEK Corp. MT7922 802.11ax PCI Express Wireless Network Adapter [14c3:0616]
        Subsystem: MEDIATEK Corp. Device [14c3:e616]
        Flags: bus master, fast devsel, latency 0, IRQ 131, IOMMU group 13
        Memory at 7810900000 (64-bit, prefetchable) [size=1M]
        Memory at 90b00000 (64-bit, non-prefetchable) [size=32K]
        Capabilities: [80] Express Endpoint, IntMsgNum 0
        Capabilities: [e0] MSI: Enable+ Count=1/32 Maskable+ 64bit+
        Capabilities: [f8] Power Management version 3
        Capabilities: [100] Vendor Specific Information: ID=1556 Rev=1 Len=008 <?>
        Capabilities: [108] Latency Tolerance Reporting
        Capabilities: [110] L1 PM Substates
        Capabilities: [200] Advanced Error Reporting
        Kernel driver in use: mt7921e
        Kernel modules: mt7921e

It drops the connection requiring a reconnect about every 10-20 minutes. Rolling back to the firmware from Feb 2024 (20240219103337) causes things to remain stable, as does disabling the power management on the card (iw dev wlp1s0 set power_save off).

Firmware from November 2024 (what came with my system), or the May 2025 firmware from linux-firmware in Gitlab, both show the issue if power management is enabled.

Cheers, let me know any other info I can provide.

Start by reproducing the mt7921e disconnects on the MT7922 with power management enabled, then compare the November 2024, May 2025, and February 2024 firmware behavior. The iw dev wlp1s0 set power_save off result provides a comparison case; done means the connection remains stable without disabling power management.