If it's older, it may need division.  It may be so overcrowded that  stalks are thinning.  Because. rhubarb takes many nutrients from the soil , it's important to divide and move it  to another location every few years.  Another possibility is wind and heavy rain; these weather conditions  can  force rhubarb stalks to flatten.

For information on growing rhubarb successfully in Minnesota, see
https://extension.umn.edu/vegetables/growing-rhubarb

The University of Minnesota has a publication about earwigs and describes ways of managing these pests.  See https://extension.umn.edu/nuisance-insects/earwigs