Here's the UAW-FCA contract.[1] This would be a "temporary layoff" in a union plant. Beyond 10 days, different rules apply. Auto plants do this during model changeovers, so it's expected. Short layoffs are unpaid. Long layoffs come under the unemployment benefits provision.

Tesla's production engineering people probably need to rearrange the production line. By now, they should know where the trouble spots are.

[1] https://uaw.org/app/uploads/2017/03/2015-agreement-productio...