Given the following configuration:

1. setup interfaces and bridge domain:
vat# sw_interface_set_flags sw_if_index 1 admin_up link_up
vat# sw_interface_set_flags sw_if_index 2 admin_up link_up
vat# bridge_domain_add_del bd_id 1 flood 1 uu-flood 1 forward 1 learn 1 arp-term 0
vat# sw_interface_set_l2_bridge sw_if_index 1 bd_id 1
vat# sw_interface_set_l2_bridge sw_if_index 2 bd_id 1

2. configure classifier:
vat# acl_add_replace ipv6 permit proto 17
vat# acl_interface_add_del sw_if_index 1 add input acl 0

When I send an IPv6 UDP packet to interface 1, the packet does not hit the rule and is dropped.

Attached pcap file with test packet used and VPP packet trace.