ping delay happend to rb951g-2hnd again,and tx power problem

hi to all.
have a RB951G-2HnD now.the ping delay happend again,about 1 minute,the delay show up once,about one to four packets will delay 40-80ms.
and the secend problem:i can’t change tx power in the “card rates” mode,only the “all rate fixed” mode works.

here are the config:
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk eap-methods=“”
group-ciphers=aes-ccm group-key-update=5m interim-update=0s
management-protection=disabled management-protection-key=“” mode=
dynamic-keys name=default radius-eap-accounting=no radius-mac-accounting=
no radius-mac-authentication=no radius-mac-caching=disabled
radius-mac-format=XX:XX:XX:XX:XX:XX radius-mac-mode=as-username
static-algo-0=none static-algo-1=none static-algo-2=none static-algo-3=
none static-key-0=“” static-key-1=“” static-key-2=“” static-key-3=“”
static-sta-private-algo=none static-sta-private-key=“”
static-transmit-key=key-0 supplicant-identity=MikroTik tls-certificate=
none tls-mode=no-certificates unicast-ciphers=aes-ccm wpa-pre-shared-key=
“” wpa2-pre-shared-key=rb951g-2hnd
/interface wireless
set 0 adaptive-noise-immunity=none allow-sharedkey=no antenna-gain=0 area=“”
arp=enabled band=2ghz-b/g/n basic-rates-a/g=6Mbps basic-rates-b=1Mbps
bridge-mode=enabled channel-width=20/40mhz-ht-above compression=no
country=no_country_set default-ap-tx-limit=0 default-authentication=yes
default-client-tx-limit=0 default-forwarding=yes dfs-mode=none
disable-running-check=no disabled=no disconnect-timeout=3s distance=
indoors frame-lifetime=0 frequency=2412 frequency-mode=manual-txpower
frequency-offset=0 hide-ssid=no ht-ampdu-priorities=0 ht-amsdu-limit=8192
ht-amsdu-threshold=8192 ht-basic-mcs=
mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7 ht-guard-interval=any
ht-rxchains=0 ht-supported-mcs=“mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,
mcs-7,mcs-8,mcs-9,mcs-10,mcs-11,mcs-12,mcs-13,mcs-14,mcs-15,mcs-16,mcs-17,
mcs-18,mcs-19,mcs-20,mcs-21,mcs-22,mcs-23” ht-txchains=0
hw-fragmentation-threshold=disabled hw-protection-mode=none
hw-protection-threshold=0 hw-retries=7 l2mtu=2290 mac-address=
D4:CA:6D:93:D3:40 max-station-count=2007 mode=ap-bridge mtu=1500
multicast-helper=default name=wlan1 noise-floor-threshold=default
nv2-cell-radius=30 nv2-noise-floor-offset=default nv2-preshared-key=“”
nv2-qos=default nv2-queue-count=2 nv2-security=disabled
on-fail-retry-time=100ms periodic-calibration=default
periodic-calibration-interval=60 preamble-mode=both
proprietary-extensions=post-2.9.25 radio-name=D4CA6D93D340
rate-selection=advanced rate-set=default scan-list=default
security-profile=default ssid=MikroTik station-bridge-clone-mac=
00:00:00:00:00:00 supported-rates-a/g=
6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps supported-rates-b=
1Mbps,2Mbps,5.5Mbps,11Mbps tdma-period-size=2 tx-power=0 tx-power-mode=
all-rates-fixed update-stats-interval=disabled wds-cost-range=50-150
wds-default-bridge=none wds-default-cost=100 wds-ignore-ssid=no wds-mode=
disabled wireless-protocol=unspecified wmm-support=disabled

Are you using the newest firmware and software?

ros v5.25 firmware3.04,

upgrage to ROS V6.1 and firmware 3.08,the newest,the same

and the tx/rx rate in the registration table is lower,now most of time is about 150/160,compare to 300/300 before.