This can happen due to the following reasons:

- Continuous-evaluation is disabled. Turn on continuous-evaluation in the forwarding profile. If continuous-evaluation is disabled, the path selection for a flow is done only when the flow starts, because an SLA compliant path is chosen. After that, the path is not switched even if it transitions between in and out of compliant state. If continuous-evaluation is enabled, then Versa checks for the availability of an SLA compliant path after every recompute-interval. If a new SLA compliant path is found, and it is of a higher priority than the current path, the flow switches to the higher priority path. 

- Long recompute interval. The path is evaluated for its SLA compliance after every recompute interval. If the recompute interval is long (for instance, two minutes), then it may take up to two minutes to determine that the path is in SLA compliance and for existing flows to switch to it. 

Refer to the article, "How do I figure out why my traffic is using Broadband instead of MPLS?" for more information.