Hello,
I don't see any "cache" entries in FT on real MX2020, JUNOS 20.2 beta:
user@router> show isis adjacency
15 Jun 2020 01:28:15 EDT
Interface System L State Hold (secs) SNPA
ae0.0 PTX-2 2 Up 19
et-19/0/0.0 Core-NCS 2 Up 23
xe-13/0/0.0 P-3 2 Up 26
user@router> show route forwarding-table extensive | grep cach
15 Jun 2020 01:28:19 EDT
user@router> show route forwarding-table summary
15 Jun 2020 01:33:46 EDT
Routing table: default.inet
Internet:
user: 9 routes
perm: 5 routes
intf: 9 routes
dest: 16 routes
Please specify the platform and JUNOS release. If You are doing this on vMX it is possible that You see flow cache entries which is an entirely different feature.
HTH
Thx
Alex