RB751U-2HnD, mac address table issue since 6.29

Since 6.29 I have an issue with mac address table on RB751U-2HnD.
ARP 10.4.8.70/00:1A:79:08:E1:D9 is present, but there’s no mac 00:1A:79:08:E1:D9 in FDB.
10.4.8.70 is my IPTV box connected to eth2 (member of bridge-local) so result is dst-traffic to that box goes to any port in bridge-local (even wlan1).

ARP is present:

> ip arp print
Flags: X - disabled, I - invalid, H - DHCP, D - dynamic, P - published
 #   ADDRESS         MAC-ADDRESS       INTERFACE
 0 D 10.4.8.70       00:1A:79:08:E1:D9 bridge-local

But there’s no MAC 00:1A:79:08:E1:D9 in FDB (must be on eth2):

 > interface bridge host print
Flags: L - local, E - external-fdb
  BRIDGE                 MAC-ADDRESS       ON-INTERFACE  AGE
L bridge-local           D4:CA:6D:55:C4:51 eth1          0s
L bridge-local           D4:CA:6D:55:C4:52 eth2          0s

It can be assumed that MAC 00:1A:79:08:E1:D9 has expired and ARP 10.4.8.70/00:1A:79:08:E1:D9 didn’t
and there’s no traffic from/to 10.4.8.70 (actually traffic was aprx. 8-10Mbps),
so I ping 10.4.8.70 from RB:

> ping 10.4.8.70 count=5
  SEQ HOST                                     SIZE TTL TIME  STATUS
    0 10.4.8.70                                  56  64 0ms
    1 10.4.8.70                                  56  64 0ms
    2 10.4.8.70                                  56  64 0ms
    3 10.4.8.70                                  56  64 0ms
    4 10.4.8.70                                  56  64 0ms
    sent=5 received=5 packet-loss=0% min-rtt=0ms avg-rtt=0ms max-rtt=0ms

But there’s again no 00:1A:79:08:E1:D9.

mac-scan find’s that 00:1A:79:08:E1:D9:

 > tool mac-scan eth2
MAC-ADDRESS       ADDRESS                AGE
D4:CA:6D:55:C4:54 10.4.8.70                0
00:1A:79:08:E1:D9 10.4.8.70                0

And it installs to FDB:

> interface bridge host print
Flags: L - local, E - external-fdb
  BRIDGE                      MAC-ADDRESS      ON-INTERFACE   AGE
  bridge-local               00:1A:79:08:E1:D9 eth2           0s
L bridge-local               D4:CA:6D:55:C4:51 eth1           0s
L bridge-local               D4:CA:6D:55:C4:52 eth2           0s

But 00:1A:79:08:E1:D9 expires after 10min (timer set on bridge-local interface).

I didn’t have that issue 'till 6.28. After 6.29 its present in 6.30 and in 6.30.2.

It seems this bug was fixed in 6.31. After upgrade to 6.31 everything good with fdb and arp.