This can be reproduced by lower the default rekey_time_limit or rekey_write_limit.

It seems to me thrussh/src/server/encrypted.rs is missing the following two lines in the corresponding client code:

self.common.write_buffer.bytes = 0;
enc.last_rekey = std::time::Instant::now();

Thanks! This was indeed missing. I’ll publish a new version of the crate on crates.io now.