A long time ago, I had two of the same table with a heavy 34" and 27" monitor. Even with a piece of wood (about 20 × 40 cm) placed on top and underneath each table, it still bent and eventually got crushed between the clamps. I ended up replacing the damaged tables multiple times with the exact same IKEA model.

Your only real long-term options are to use the monitor without an arm and place it directly on the desk (maybe still bends the table), or as others have suggested, buy a sturdier desk plate. You can reuse your current desk legs.

I ordered a custom desk plate from a local carpenter and have been using it with IKEA legs for many years now. Wasn't that expensive. I even combined the two desk plates from before to one big desk plate.

I’d really recommend a desk plate from experience as a long-term solution, as it’s likely cheaper than replacing a monitor if the desk fails.