I am experiencing a severe stability issue with my TP-Link Deco X50-5G (Hardware Version V2) while using an O2 Germany 5G SIM card.
The Internet connection drops  for 10–40 seconds under specific but easily reproducible conditions. This issue occurs several times per hour and makes the device nearly unusable without workarounds.
Below are all details I have gathered after extensive testing.
 Problem summary
The Internet connection periodically freezes completely  or dramatically slowing down (no website loads, no ping replies) for 10–40 seconds, then recovers automatically  or  by reboot or by apn change. Mobile data  toggle did not helping .
During these freezes, packet loss reaches 50–100% to all public destinations .

VPN traffic (AnyConnect, WireGuard, OpenVPN) remains stable during those outages — zero packet loss through the VPN tunnel.
The problem affects both wired and Wi-Fi clients.
Local network (LAN/Wi-Fi) stays up — only WAN connectivity drops.
Reproducible triggers
The issue is consistently reproducible in the following cases:
When a new device connects to the Deco Wi-Fi or Ethernet network — immediately causes packet loss on all clients.
When opening websites that initiate many concurrent connections (for example: speediest , amazon , news portals, etc.) — the 5g link freezes instantly.
When running high-burst short TCP sessions (e.g. multi-threaded downloads, latency tests).
When switching between domains under different TLDs (especially  ru and . de) — often leads to a 10–40s “blackout”.
During these freezes, ping to O2 DNS servers (from router’s configuration) remains stable, but pings to public IPs fail completely.

LED still solid white during those problems. 
Steps already taken
I have performed multiple tests and mitigations:
Disabled IPv6 Slightly improves stability but does not fix the issue.

Forced 4G (LTE only) mode Greatly reduces frequency of freezes — confirms the issue is in the 5G modem path.

 Tested multiple APNs  No difference.

Rebooted and factory-reset Deco No change.

Tried static DNS  Google and Cloudflare No improvement.

Connected via VPN directly on PC (Cisco AnyConnect / WireGuard)Completely stable connection — zero packet loss

Used VPN at router level (Deco built-in)  improvement  but not fully — router still freezes periodically.
 

 
Please confirm whether this issue is already known for the Deco X50-5G V2   in 5G networks.
If possible, provide a beta firmware   update that addresses these instability symptoms.
Advise if there are recommended APN, MTU, or DNS settings for O₂ Germany that improve stability.
Tell me if I can collect additional debug logs  to assist your engineering team.