monitor arm keeps tilting down

Mount-It! Footrest with Massaging Bead | Adjustable Height and Tilt Office Foot Rest Stool for Under Desk Support | 5 Height Settings, 3 Tilt Settings

Mount-It! Glass Desktop Monitor Stand Riser | Raised Laptop Stand Organizer | 22 Inches Wide Clear Tempered Glass | Supports up to 44 Pounds

Mount-It! Extra Long Monitor Desk Riser, Desktop Organizer for Double Computer Screens, Laptops, Desktops, TVs, 39 Inches Extra Wide, 44 Lbs. Capacity

Mount-It! Height Adjustable Single Monitor Riser | Metal Mesh Computer Screen Platform | Desktop Riser for Laptop Monitor & Printer | 44 Lbs. Capacity

Mount-It! Ergonomic Foot Rest Under Desk | Adjustable Tilt Footrest w/ Textured Massage Surface | Work Footstool Under Office Desk Foot Support, Black

Mount-It! Ergonomic Footrest, Tilt Adjustable Individual Platforms, Height Adjustable Foot Rest with Massage Surface, Under Desk Foot Stool for Office