mac80211: HT disabled ("required MCSes not supported") on Xfinity network, RTL8852BE (rtw89) capped at ~20 Mbps on kernel 7.0.0

Hello,

I'm reporting a throughput regression that appears to match an issue
discussed on the Arch Linux forums
(https://bbs.archlinux.org/viewtopic.php?id=313033), where other users
ran into the same symptom.

- Wi-Fi throughput dropped from near-gigabit speeds to a hard ~20 Mbps cap.
- Confirmed not an ISP or router issue: booting an older kernel
(6.8.0-138-generic) on the same machine, same hardware, same network,
restores normal (near-plan) speeds.
- Confirmed not a driver-installation issue: the in-tree rtw89 driver
is in use in both cases (no custom/out-of-tree driver).
- The regression is reproducible simply by booting the newer kernel
vs. the older one -- no other configuration changed.

Hardware / environment:
- Wi-Fi chipset: Realtek RTL8852BE (rtw89, rtw8852be), PCIe
- Driver in use: in-tree rtw89 (rtw89_8852be / rtw89_pci / rtw89_core
/ mac80211 / cfg80211)
- Firmware: rtw8852b_fw-1.bin, version 0.29.29.5 (da87cccd), cmd version 0
- OS: Linux Mint
- Broken kernel: 7.0.0-30-generic
- Working kernel: 6.8.0-138-generic (confirmed via dpkg -l | grep
linux-image and booting via GRUB "Advanced options")
- ISP: Comcast Xfinity, 1 Gbps plan

Symptom pattern:
On the affected kernel, dmesg / journal shows mac80211 disabling HT
("required MCSes not supported, disabling HT"), and the link
negotiates down to a 20 MHz, no-HT connection instead of HT/VHT/HE,
which caps throughput at roughly 20 Mbps regardless of my ISP plan
speed.

The fix that resolved this for other users in the linked Arch thread
is a community patch that removes mac80211's basic MCS/NSS check
(github.com/WoodyWoodster/mac80211-mcs-patch). That fix has since been
picked up into Arch's own kernel package as of version 7.0.13.

I'm submitting this to add a confirmed data point (RTL8852BE, kernel
7.0.0, Xfinity) in case it's useful for tracking or prioritizing a fix
upstream.

Happy to provide any other diagnostics that would help.