Back up and correct alignment. The drive needs to engage the hemmed edges properly at the corner; if it misses, the joint is not finished correctly.
Make the metal fit right before sealing, insulating, or moving on. S-and-drive problems usually come from alignment, seating, support, damage, or wrong connector pattern.
Do not use force, screws, tape, or mastic to hide a bad mechanical fit.
Check
Stop driving. Do not try to extend the drive past the S-lock - a drive that misses the corner is not connected at that corner.
Back the drive out to expose the corner area and look at what happened: did the drive skip over the S-lock lip, did the duct shift, or is the corner out of square?
Re-seat the S-cleat at the corner, making sure the raw edge of the duct is fully inside the S channel before restarting.
Hold the duct square during the drive restart - have someone support the section so it cannot shift and throw the drive off the S-lock again.
After driving, visually inspect both corners to confirm the drive engages the S-lock fully at each end.
Steps
Stop driving. Do not try to extend the drive past the S-lock - a drive that misses the corner is not connected at that corner.
Back the drive out to expose the corner area and look at what happened: did the drive skip over the S-lock lip, did the duct shift, or is the corner out of square?
Re-seat the S-cleat at the corner, making sure the raw edge of the duct is fully inside the S channel before restarting.
Hold the duct square during the drive restart - have someone support the section so it cannot shift and throw the drive off the S-lock again.
After driving, visually inspect both corners to confirm the drive engages the S-lock fully at each end.
Say this to your foreman
My drive is missing the S-lock at the corner on the [top/bottom]. I backed it out. I think the issue is [duct shifted / corner out of square / S-lock not aligned]. Do you want me to re-seat and retry, or look at squaring the section first?