Campbell Robertson explains why the strike marches on:
According to people involved with the negotiations on both sides, the league and the union had found common ground on the rules that apply to the load-in, the lengthy period when shows are moving into theaters. But Local 1 did not agree [on Sunday night] to the league’s proposed changes to the rules governing shows that are up and running.
In the recently expired contract, stagehands could be called for one “continuity hour” to do work before or after a show; any extra work beyond that required a four-hour work call. The producers had made various proposals to loosen this requirement.
The league had also been trying to change rules that limited the kind of work stagehands are allowed to do during certain work calls. A package of proposed raises was contingent on how much flexibility the league achieved.
Repeat: it's not about the load-in anymore.