IPv6 Flowspec isn't displayed correctly with "show route"

[Alex D.]

Hello,

i have a problem when i try to get infos about a specific IPv6 FlowSpec
route by issuing "show route <route>" or "show route <route> all".
It works, when i don't specify a particular route:

bird> show route
~
~
Table flowspec_table_v6:
flow6 { dst 2a02:5a0:1212:1212::199/128; src 2a02:3f8::1/128; dport 389;
}  [flowspec_v6 2019-11-08] * (200)
flow6 { dst 2a02:5a0:15ff:3::1/128; src ::/0; next header 58; }
[vs_dis_r1_6838 23:46:47.465 from 172.28.18.113] * (100) [AS9063i]
bird>

... and it also works when i specify a route which is imported in BGP
from a local static route:

bird> show route flow6 { dst 2a02:5a0:1212:1212::199/128; src
2a02:3f8::1/128; dport 389; }
Table flowspec_table_v6:
flow6 { dst 2a02:5a0:1212:1212::199/128; src 2a02:3f8::1/128; dport 389;
}  [flowspec_v6 2019-11-08] * (200)

bird> show route flow6 { dst 2a02:5a0:1212:1212::199/128; src
2a02:3f8::1/128; dport 389; } all
Table flowspec_table_v6:
flow6 { dst 2a02:5a0:1212:1212::199/128; src 2a02:3f8::1/128; dport 389;
}  [flowspec_v6 2019-11-08] * (200)
         Type: static univ
         BGP.ext_community: (generic, 0x80060000, 0x0)
bird>

But when I try to show a route received via eBGP, output wrongly states
that the network could ne be found:

bird> show route flow6 { dst 2a02:5a0:15ff:3::1/128; src ::/0; next
header 58; }
Network not found
bird>
bird> show route flow6 { dst 2a02:5a0:15ff:3::1/128; src ::/0; next
header 58; } all
Network not found
bird>

I tried BIRD versions 2.2, 2.4 and 2.7. I could reproduce the issue in
all versions. With IPv4 Flowspec, all output (for local static as well
as eBGP-learned) is fine.
Does anybody noticed the same behaviour ? Or is it a known bug ? If you
need further informations, don't hesitate to ask for it.

Thanks in advance for your replies.
Regards,
Alex