Error writing file 'binlog' (errno: 2 - No such file or directory)

[Eagle Apk]

We are using MYSQL 8.0.20 Community Edition on Oracle Linux 7.8 (RHEL). On one server we are running master database and using row based replication to a slave on another server via bin-log. Replication is running OK (we use Percona toolkit to perform checksums). Had an issue suddenly when updating any records caused the following intermittent error:

1026: Error writing file 'binlog' (errno: 2 - No such file or directory)

This started very early in the morning one day and was intermittent throughout the day and suddenly the error stopped. No errors recorded in the MYSQL log files as far as I can see on either server (only in the log files from our application REST API that connects to the database to query and update records).

Also noticed the above error in MYSQL Workbench when trying to update records - again this was intermittent.

We don't have 'binlog' file per say

-rw-r-----. 1 mysql mysql 392106655 Aug 24 11:17 binlog.000025
-rw-r-----. 1 mysql mysql 1073790505 Sep 1 09:02 binlog.000026
-rw-r-----. 1 mysql mysql 598606158 Sep 11 13:12 binlog.000027
-rw-r-----. 1 mysql mysql 290988040 Sep 17 17:30 binlog.000028

Not sure why 'binlog' was being updated to attempting to be updated - seems like it could not work out which binary log file to update. Show master status reveals:

File: binlog.000028
Position: 291444378
Binlog_Do_DB
Binlog_Ignore_DB

Bin log cache setup:

Bin log cache size: 32768
Max bin log cache size: 18446744073709547520
Binlog format: ROW

We do have tables where average row size is above bin log cache size (around 88K on average).

Not sure where to look, doesn't look like any memory or disk issues on the server. We have been running this setup for a while but with increased load of late.