OVS 2.9.0 has issues with group tables collecting packets. This fails many of the csit tests. The bug below details the problem and the fix. The fix has been upstreamed but a newer OVS version has not been released yet.

https://bugzilla.redhat.com/show_bug.cgi?id=1544892

The upstream fix is: https://github.com/openvswitch/ovs/commit/058d3a4afddd4db6bf052c71ff431a59fa5a0335. Erics comment about the patches pushed upstream:
Applied upstream:

14ebc6c199a7 ("tests/ofproto-dpif: New test for action_set after traversing patch port")
118b21d93f55 ("ofproto-dpif-xlate: translate action_set in clone action")

It has also been backported to branch-2.9.

A possible workaround is to install the ovs package mentioned in the bugzilla. The basic idea is to add the repo config and then install ovs from that repo. This could be done in a couple ways:

1. In the current csit vm images, ovs is installed via the packer scripts. Add the repo config there and install ovs. Also remove the "sudo yum versionlock add openvswitch" from the run.sh script which is what is locking the ovs version at 2.7.3.

2. After the vms are started, ssh over to the vms, config the repo and install ovs.

I suspect updating with [1] is the easier solution, but it does require building the image.