Zerotier problem in Openwrt

Hello
I have router Linksys E1550 with Openwrt firmware in two sites and install Zerotier in this two routers my network map like that


in Zerotier Account control make Managed Routes
10.1.1.0/24 via 10.147.17.179

10.147.17.0/24 (LAN)

10.2.2.0/24 via 10.147.17.126

and make Firewall setting like in GITHUB Wiki to each site can see local network of the other

when laptop do ping two Issable , ping is very good
but when laptop do ping to two router or any device in two sites is so bad and Big delay and cuting
and same problem when PC in Site A do Ping to any device in Site B or PC in Site B do PIng to any device in Site A so bad and Big delay and cuting
i want know what problem and how solve it
And any one have other firmware to linksys e1550 support zerotier

Any one can solve this problem???