Mediatek MT7921K slow download on 5 GHz band

Greetings, this is my first post on the forum.

I’ve installed a new wifi network card in my machine, and it is based on the mediatek 7921k chip. The 2.4 GHz band works fine, the negotiated speed with my router is just over 200 Mbps for up/down links, and speed tests confirm that I can achieve 120 Mbp/s download in reality. What is peculiar is the behavior at 5 GHz, where the negotiated upload speed with the router is close to 1 Gbit/s, but download is around meager 10 Mbps. When dual booting to windows, the card meets expectations (I reach my ISP 200/20 Mbps limit), so it is not a hardware fault. I’m stumped what could be the issue.

$ uname -r
$ inxi -Fazy
  Device-1: MEDIATEK MT7921K Wi-Fi 6E 80MHz driver: mt7921e v: kernel pcie:
    gen: 2 speed: 5 GT/s lanes: 1 bus-ID: 02:00.0 chip-ID: 14c3:0608
    class-ID: 0280
  IF: wlp2s0 state: up mac: <filter>
  Info: services: NetworkManager, systemd-timesyncd, wpa_supplicant
$ sudo dmesg | grep mt7921e
[    4.714807] mt7921e 0000:02:00.0: ASIC revision: 79610010
[    4.798637] mt7921e 0000:02:00.0: HW/SW Version: 0x8a108a10, Build Time: 20240219110958a
[    4.811906] mt7921e 0000:02:00.0: WM Firmware Version: ____010000, Build Time: 20240219111038
[    6.415485] mt7921e 0000:02:00.0 wlp2s0: renamed from wlan0