There isn't an obvious way to select a run of components in Reorder Mode. According to the Help Center, you can select items one at a time using control/command+click (depending on whether you have a Mac/PC). Intuitively according to normal computer operations, if I hold down the shift key, I should be able to select an inclusive run of components. Instead, it opens a new browser for me (Mac user).
Dev/Pri was unable to duplicate this problem at our November 3, 2020 meeting. It may have been fixed since 2.6.0. We are therefore closing this ticket, please reopen it if the problem recurs.