Don't see macs in fdb table on x450a-24x

[Victor_Vit]

Hello.
There is a problem with adding some random client's macs in fdb table on extreme x450a-24x firmware version 15.3.5.2.
I see this macs on previous switches, clients get ip by DHCP, but when I do
show fdb 11:11:11:11:11:11 - I don't see this mac (for exemple) in fdb table. Extreme switch works also as gateway for clients and iparp record is absent.
BUT, when I do
clear fdb vlan VlanClient1
and after
show fdb 11:11:11:11:11:11
I see this mac on switch. Also appears record in iparp table.
Number of all macs is near 4200-4300

Any ideas what is it?

[Victor_Vit]

pgs.20 # sh fdb stats

Total: 4318 Static: 0 Perm: 0 Dyn: 4318 Dropped: 0
FDB Aging time: 300

pgs.21 # sh iproute reserved-entries statistics
|-----In HW Route Table-----| |-------In HW L3 Hash Table------|
# Used Routes # IPv4 Hosts IPv4 IPv4 IPv6 IPv4 IPv6
Slot Type IPv4 IPv6 Local Remote Local Rem. Local MCast MCast
---- --------------- ------- ------ ------ ------ ----- ----- ----- ------ ------
1 X450a-24x 228 0 2922 0 0 0 0 207 0

pgs.22 # debug hal show forwarding distributions system
L3 Hash Table Utilization:
Used/Available: 212/8192

L3 Hash Table Bucket Distribution:
Total: 1024 buckets
[ 0 entries]: 835 buckets
[ 1 entry]: 167 buckets
[ 2 entries]: 21 buckets
[ 3 entries]: 1 bucket
[ 4 entries]: 0 buckets
[ 5 entries]: 0 buckets
[ 6 entries]: 0 buckets
[ 7 entries]: 0 buckets
[ 8 entries]: 0 buckets