Let’s remember first how strict navigation is meant to work:
“Navigate along the route without shortcuts, i.e. follow the route strictly from one waypoint to another. When go off route, the rerouting tries to resume to the last omitted waypoint.”
When (re)start navigation after 1st via point, strict mode considers off route situation and “rerouting tries to resume to the last omitted waypoint”.
If want more flexibility on strict navigation there is a discussion for pause / resume navigation:
(or use a flexible mode like “Next waypoint” to exit / resume navigation anywhere)