[java] My ISP blocks port 25565 (Minecraft Java), how can I play?

Hi! I recently moved and switched internet providers, and since then I can't connect to any Minecraft Java server. Before moving I could play without any problem, using the same PC and account.

What I've already tried:

• Test-NetConnection to port 25565 returns False, but port 443 returns True and ping works. DNS resolves fine.
• With my phone's hotspot, port 25565 goes through (True), so my PC is fine.
• I checked my router: no port filtering, firewall set to Low, no parental control, no MAC/IP filtering, no port triggers.
• My WAN IP is private (10.x), so I'm behind CGNAT.
• With a VPN (Cloudflare WARP) the port goes through and I can play, but almost every server detects the VPN and kicks me. Only two or three let me in.
• The VPN also makes my internet really slow.
• I already filed a complaint with my ISP, but they are slow to reply.

Everything points to an outbound block by my ISP, not something on my router or PC. Does anyone know how to get around it without servers detecting it as a VPN? Or a way to force a different port?

Thanks!