Seems some representatives in the Minnesota senate didn't want to abide with a negotiated contract for some Teamsters. The political fighting was along party lines.

Teamsters Local 320 Applauds Minnesota Governor Tim Walz for Supporting Unions and Collective Bargaining
Teamsters Local 320 congratulates Governor Tim Walz for standing with Teamsters and other union state employees who are counting on their now-ratified labor agreements, which promise raises in the second year. Nearly 1,000 Teamsters Local 320 members were affected, in addition to thousands of other state employees.
On May 11, the Minnesota House of Representatives voted to ratify the collective bargaining agreements as submitted. On May 17, the Minnesota State Senate voted to ratify the agreements, but stripped the negotiated raises from the second year of the contract.
Senate Republican leadership came to the Teamsters and urged Local 320 to renegotiate their contract to strip the raises out from the second year of the contract. Teamsters Local 320 refused, standing with its membership and principles of free collective bargaining.
"What should have been a straightforward process became a rollercoaster ride of partisanship and union bashing," said Sami Gabriel, Local 320 President and Chief Negotiator. "The agreements were negotiated in good faith and we are happy that Governor Walz pushed through the agreements unscathed from legislative interference."