Shot in the dark: maybe your fee negotiation policies were out of sync. Lightning nodes that run on "blocks only mode," and many that run on neutrino, perpetually think the feerate is 1 sat per byte. If the blockchain's actual feerate rises above that, they will refuse to negotiate with their peers to use a higher feerate for htlcs and for updated force closure transactions. The refusal to negotate a higher feerate can lead other nodes to force close on them.

This is also why force closure transactions typically use a fee about 3 times higher than the current feerate. The high fee gives you time to negotiate or initiate a force closure using the force closure transaction you created with the previously-negotiated feerate. Even if fees are spiking, they are unlikely to get 3 times higher than the previously-negotiated feerate before you can negotiate again or force close on your peer.