From The Central States Pension Fund website...
If the loss of your adjustable benefits was triggered by your employer becoming subject to the Default Schedule (either through negotiating the Default Schedule in a new Collective Bargaining Agreement or having the Default Schedule imposed by law because the negotiating parties are unable to reach an agreement after 180 days), unlike a Rehabilitation Plan Withdrawal, there is no requirement that you cease working for the employer within 60 days. However, as in the case of a Rehabilitation Plan Withdrawal, you need to go to work for a Contributing Employer to the Central States Pension Fund that contributes under the Primary Schedule and earn an additional year of Contributory Service Credit (40 weeks / 180 days in a Plan year) to have your adjustable benefits restored. And, as in the case of a Rehabilitation Plan Withdrawal, your status going forward will be determined by the status of your most recent Contributing Employer.
https://mycentralstatespension.org/...s_there_any_way_to_regain_those_benefits.aspx