I need this device as simple AP, you connect a ethernet cable and connecting devices to wifi ssid the must reach the cabled side, but a simple ping take crazy timing: sometimes 70 ms sometimes 700ms.

Can you please say if there is something wrong in this configuration?

# apr/12/2019 11:49:37 by RouterOS 6.44.2
# software id = ABSX-SYDB
#
# model = RouterBOARD mAP 2nD
/interface bridge
add fast-forward=no name=BRIDGEWIFI
/interface ethernet
set [ find default-name=ether1 ] advertise=\
10M-half,10M-full,100M-half,100M-full,1000M-half,1000M-full name=LAN_ETH1
set [ find default-name=ether2 ] advertise=\
10M-half,10M-full,100M-half,100M-full,1000M-half,1000M-full
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
add authentication-types=wpa-psk,wpa2-psk eap-methods="" group-ciphers=\
tkip,aes-ccm group-key-update=15m management-protection=allowed mode=\
dynamic-keys name=WLAN1 supplicant-identity="" unicast-ciphers=\
tkip,aes-ccm wpa-pre-shared-key=lUGLIO2015 wpa2-pre-shared-key=lUGLIO2015
/interface wireless
set [ find default-name=wlan1 ] antenna-gain=2 band=2ghz-b/g/n channel-width=\
20/40mhz-Ce country=italy disabled=no frequency=auto frequency-mode=\
regulatory-domain installation=indoor mode=ap-bridge security-profile=\
WLAN1 ssid=Not_FOUND_test wireless-protocol=802.11
/interface wireless nstreme
set wlan1 enable-polling=no
/ip hotspot profile
set [ find default=yes ] html-directory=flash/hotspot
/ip pool
add name=dhcp_pool0 ranges=192.168.1.200-192.168.1.230
/ip dhcp-server
add address-pool=dhcp_pool0 authoritative=after-2sec-delay interface=\
BRIDGEWIFI lease-time=3d10m name=dhcp1
/snmp community
set [ find default=yes ] addresses=0.0.0.0/0
/interface bridge port
add bridge=BRIDGEWIFI interface=wlan1
add bridge=BRIDGEWIFI hw=no interface=ether2
add bridge=BRIDGEWIFI hw=no interface=LAN_ETH1
/ip dhcp-client
add dhcp-options=hostname,clientid disabled=no interface=BRIDGEWIFI
/ip dhcp-server network
add address=192.168.1.0/24 dns-server=8.8.8.8 gateway=192.168.1.1
/ip dns
set allow-remote-requests=yes servers=8.8.8.8
/ip firewall nat
add action=masquerade chain=srcnat out-interface=BRIDGEWIFI
/ip smb shares
set [ find default=yes ] directory=/pub
/system clock
set time-zone-name=Europe/Rome

Thanks, BR

Remove NAT

I would suggest to do a scan in wireless and see what other access points are transmitting near you. Try to find the most unused channel. Give access to only one device to your wifi and check its signal. Once that you are sure that the signal between your device and the mAP is OK, try working and pinging. If you see improvement, permit other devices to connect and observe their signal and their impact in the network (if any).

1) fast-forward=yes
2) disable all the packages you don't use , routing/hotspot/ipv6/security/ppp etc
3) set /queue interface to hardware queue only on both interfaces.
4) bridge ports hw=YES

Thank you for your replies!
The issues seems solved, here the working config: