MySQL Master-Master - different bin logs

We have Master <> Master replication. After some start-stop issues - I found some odds in replication.

First - on both boxes we have an error:

160226 10:08:59 [Note] Slave I/O thread: connected to master 'user@172.**.**.51:3306',replication started in log
'mysql-bin.000210' at position 107
160226 10:08:59 [ERROR] Error reading packet from server: Could not find first log file name in binary log index file (
server_errno=1236)
160226 10:08:59 [ERROR] Slave I/O: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log
file name in binary log index file', Error_code: 1236
160226 10:08:59 [Note] Slave I/O thread exiting, read up to log 'mysql-bin.000210', position 107

Status on both nodes also says:

      Master_Log_File: mysql-bin.000210
  Read_Master_Log_Pos: 107
       Relay_Log_File: relay.000629
        Relay_Log_Pos: 4
Relay_Master_Log_File: mysql-bin.000210
...
  Exec_Master_Log_Pos: 107
      Relay_Log_Space: 107
                Last_IO_Errno: 1236
        Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in
binary log index file'

I found a possible solution to fix a 1236 error - jusr move replication to last bin-log at first position, i.e.:

STOP SLAVE;
CHANGE MASTER TO MASTER_LOG_POS = 0;
CHANGE MASTER TO MASTER_LOG_FILE = 'mysql-bin.0000LASTLOGNUM';
START SLAVE;

But here is what confused me.

Master_1:

# ls -l /var/log/mysql/mysql-bin.*
-rw-rw---- 1 mysql adm  126 Feb 26 09:56 /var/log/mysql/mysql-bin.000213
-rw-rw---- 1 mysql adm  126 Feb 26 10:15 /var/log/mysql/mysql-bin.000214
-rw-rw---- 1 mysql adm 1054 Feb 26 11:13 /var/log/mysql/mysql-bin.000215
-rw-rw---- 1 mysql adm   96 Feb 26 10:15 /var/log/mysql/mysql-bin.index

While Master_2 have:

# ls -l /var/log/mysql/mysql-bin.*
-rw-rw---- 1 mysql adm 126 Feb 26 07:26 /var/log/mysql/mysql-bin.000212
-rw-rw---- 1 mysql adm 107 Feb 26 09:39 /var/log/mysql/mysql-bin.000213
-rw-rw---- 1 mysql adm  64 Feb 26 09:39 /var/log/mysql/mysql-bin.index

What is the correct way then?

Set CHANGE MASTER TO MASTER_LOG_FILE = 'mysql-bin.000215'; on Mater_1? What then to do on the Master_2?

P.S. In fact - I can just drop && recreate databases on both hosts - there is no sensitive data at this moment and this must "reload" replication process (amirite?). But out of curiosity - what's wrong with those replications?