Only 1 in 4 PC in the same subnet can ping my DC/DNS Server in Packet Tracer? (file in post)

Hi everyone,

first of all i'm using packet tracer 7.3 so maybe that could be the problem. i'm a student and i'm still learning so maybe i forgot something but i can't figure it out.

So i have 3 subnet linked with 2 routers connected in serial DCE. Each subnet has its own switch and i think it's all configured as it should. Computers get IP addresses via DHCP that i first configured on each router. Both servers on the left are static 172.17.0.5 and 172.17.0.6 respectively.

Here's the plan of my project.

My problem is that in the 172.17.64.0 network, only the PC1 (DHCP ip) can ping my DC/DNS (172.17.0.6) in the 172.17.0.0 network. Weird thing is that they all can ping both routers, so they can ping externally. I really dont get how only one computer can make it but not the other ones.

Sometimes two or three PCs can ping the server, but i have to restart the app. Like wtf?

Static routes are well configured i think. So maybe someone could help me with that problem.

Here's the pkt file so you can open it

Thanks in advance