They did get a pay raise, but the main issue was over paid sick days and this was denied.
My only small sympathy is that this was still at the tail end of the pandemic. So the strike could have legitimately made things really bad and accelerated a recession.
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Good news: There were still negotiations, and mid-february 2023 a few unions announces a deal that would give them 4 sick days + 3 personal days to convert to sick days. They apparently credit the senate for putting pressure on the railroads to allow this.
So despite calling off the strikes, there was essentially more negotiations behind the scene to prevent long term damages to morale (i.e. workers simply retiring early or otherwise leaving the industry).