Only some apps allow manual node changes, hive-engine just added it. I don't know if splinterlands has an option to switch nodes, if not it's stuck on whatever node, working or otherwise.
Every app should give the option to switch nodes (or automatically switch nodes), if some are acting up.
It came back shortly after the post went live.
It was gone for 2 or 3 days.
I agree node switching should be available.