I found Onion SMP and it is a survival server that says it supports crossplay on 1.21.11.
It has claims so your builds can stay safe. Keep inventory is on so dying is not a huge disaster.
You can use rtp to get around and start fresh spots. It also has combat log protection and teams so people can play together and not dip out of fights.
Onion SMP Crossplay 1.21.11 Survival
Casual Survival GameplayChill survival worldGrief Protection Toolssmall group multiplayerVanilla Survival Vibes
GG.MINEWIND.NET New Server IPLuckyGem SMP Fresh Semi Vanilla Crossplay
LuckyGem SMP is a fresh semi vanilla survival server with crossplay so Java and Bedrock players can join together.
It has a fully custom spawn and a world that feels new and ready to be shaped. There are also big showcase areas like a shopping district and a nether hub so you can travel and trade and just look around.
The server runs weekly competitions with big rewards. The challenges change and can be stuff like building mining redstone and PvE.
There are tons of custom advancements to chase plus cosmetic datapacks for style. You can also collect special staff collectibles that give real benefits like moving a spawner after you collect enough.
The economy is player driven and diamond based. The community seems active with friendly staff and updates based on player feedback.GG.MINEWIND.NET New Server IP