Unstable connection on StormFiber (50Mbps) with TP-Link AX55 (ONT in Bridge Mode + Cloudflare DoH) — Looking for setup advice

Hey everyone,

I'm having stability issues with my home network setup and could use some advice on what I might be missing or doing wrong.

My Current Setup:

ISP: StormFiber 50 Mbps

ONT: Provided by ISP, running in Bridge Mode

Main Router: TP-Link Archer AX55 (handling dial-up/routing)

DNS Settings: Using Cloudflare IPv4 (1.1.1.1 / 1.0.0.1) with DNS over HTTPS (DoH) enabled

IPv6: Completely disabled

Wi-Fi: Split into distinct 2.4 GHz and 5 GHz SSIDs

Despite having a clean setup on paper, the internet still feels inconsistent/unstable (random lag spikes, micro-freezes during browsing, etc.).

Has anyone run into similar issues with the AX55 or StormFiber in bridge mode? Are there specific WAN settings (like MTU/MSS adjustments), hardware acceleration tweaks, or Wi-Fi settings on the AX55 I should look into?

Any suggestions would be greatly appreciated!