MPLS Option A | Packet loss on specific source IP?

Hi Guys,

I'm currently reviewing 1 issue and just want to seek your inputs about the current setup and the problem.

Topology: https://ibb.co/HTTKg5b

The setup is there's 2 ISP involve (back-to-back vrf exchange between ISPA and B), Now the issue here's is that when SIP: 192.168.100.1 pings x.x.x.169 of ISP A IP packet loss exist while no packet loss when pinging ISP B IP(x.x.x.170).

- Ping test from CE to ISP A IP CUST_A#ping x.x.x.169 source 192.168.100.1 re 100 Type escape sequence to abort. Sending 100, 100-byte ICMP Echos to x.x.x.169, timeout is 2 seconds: Packet sent with a source address of 192.168.100.1 !!.!!!.....!.!!.!...!!!!!!!.!!..!.!!...!!.!.!.!.....!!!!.!!.!.....!... !!!.!!.!..!!.!.!!!!.!!.!!!..!! Success rate is 54 percent (54/100), round-trip min/avg/max = 30/35/70 ms CUST_A#ping x.x.x.129 source 192.168.200.1 re 100 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Success rate is 100 percent (100/100), round-trip min/avg/max = 30/35/60 ms - Ping test from CE to ISP B IP CUST_A#ping x.x.x.170 source 192.168.100.1 re 100 Type escape sequence to abort. Sending 100, 100-byte ICMP Echos to x.x.x.170, timeout is 2 seconds: Packet sent with a source address of 192.168.100.1 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! - Routing From ISP A Routing entry for 192.168.100.0/24 Known via "bgp x", distance 20, metric 0 Tag 37107, type external Routing Descriptor Blocks x.x.x.170, from x.x.x.170, BGP multi path Route metric is 0 x.x.x.129, from x.x.x.129, BGP multi path Route metric is 0 No advertising protos. Routing entry for 192.168.200.0/23 Known via "bgp x", distance 20, metric 0 Tag 37107, type external Installed Dec 27 09:01:01.620 for 2d07h Routing Descriptor Blocks x.x.x.170, from x.x.x.170, BGP multi path Route metric is 0 x.x.x.129, from x.x.x.129, BGP multi path Route metric is 0 No advertising protos. 

So I'm thinking this could be a circuit issue between 2 ISP but when I tried a different source IP noticed that there's no packet loss. Conduct a reachability from CE router block (192.168.100.0 & .200.0) towards to ISP B IP but unable to detected packet on both link facing ISP A. Also note that issue also happens on both ISP A link when CE pings sourcing to 192.168.100.x.

I do have access to ISP A and I'm thinking what could possibly go wrong. Let me know if I have missed.

1. no packet loss on ISP A to ISP B p2p ip addresses / no congestion.
2. Does the BGP multi path can affect the traffic ? (i believe should not affect since able to see the p2p and bgp peering's are stable).
3. No ACL or some sort of filtering applied on ISP A interface.
4. IPS/FW on customer side?

Thanks in advance