Hi,
this is expected behavior. See http://www.juniper.net/documentation/en_US/junos14.1/topics/reference/configuration-
statement/maximum-paths-edit-routing-options.html for more details. It says:
<snip>
The maximum-paths statement is similar to the maximum-prefixesstatement. The maximum-prefixes statement limits the number of unique destinations in a routing instance. For example, suppose a routing instance has the following routes:
OSPF 10.10.10.0/24 ISIS 10.10.10.0/24
These are two routes, but only one destination (prefix). The maximum-paths limit applies the total number of routes (two). The maximum-prefixes limit applies to the total number of unique prefixes (one).
...
When the number of routes reaches the path-limit value, then additional routes are rejected.
</snip>
Cheers,
Carsten