TiFlash failed to send store heartbeat to pd while alive

[CalvinNeo]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

One tiflash node become "disconnect store", which means PD does not receive store heartbeat from the tiflash node for more than 20 seconds.

By default, every 10 second TiFlash/TiKV send store heartbeat to PD. And according to the metrics, TiFlash did not send store heartbeat to PD at that time

Maybe related with massive remove-peer requests

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiFlash version? (Required)

v6.5.6