AT commands fail on nrf91 modem on 50% of custom boardshttps://devzone.nordicsemi.com/f/nordic-q-a/126076/at-commands-fail-on-nrf91-modem-on-50-of-custom-boardsHi, I am using nrf9151 as a modem running SLM. When SLM comes up, it throws this error. This is a new board run and 50% of the boards show this issue. I appreciate there may be a couple of things that could be the cause of this issue. I would like anyen-USTelligent Community 13Fri, 02 Jan 2026 09:29:13 GMTRE: AT commands fail on nrf91 modem on 50% of custom boardshttps://devzone.nordicsemi.com/thread/557800?ContentTypeID=1Fri, 02 Jan 2026 09:29:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ae9c6987-82e1-4d52-89b0-dade22169db5katarina8<p>The fact that AT commands are failing on half of the new nrf9151 boards is a real headache regarding hardware stability. As a web developer in London, I find this meticulous troubleshooting process requires intense concentration, reminiscent of conquering the tricky corners in <a href="https://drift-boss.lol">Drift Boss</a> to keep everything on track. I hope you find the cause and successfully fix the remaining boards soon.</p><div style="clear:both;"></div>RE: AT commands fail on nrf91 modem on 50% of custom boardshttps://devzone.nordicsemi.com/thread/556736?ContentTypeID=1Wed, 10 Dec 2025 20:01:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:abd3eed7-eb33-4a01-ad82-9a96ce3d40bfHoovinSchoovin<p>Update: some boards had bad modem firmwares on it. Updating this has fixed the issue.&nbsp;</p><div style="clear:both;"></div>