There is a paragraph in tips and notes that says:

"In addition, when a verb stem ends in "-s", second and third person plural forms will look the same: lesen (to read) - du liest, er liest

This is because the "-s-" from "du …-st" and the "-s" from the verb stem merge."

By "second and third person plural forms" you mean "second and third person SINGULAR forms", right?