I ran a few firmware updates on our Cisco Phones which are mostly SPA504G. After a few weeks of running 7.5.2a/b without problems on two test phones I deployed the update to the rest of the phones. The FW is mostly functional and stable but it brought to light one issue worth mentioning. Any Agent Login/Logout or custom speed dial BLF lights set on the units or side cars remain orange indefinitely. The buttons do appear to function normally. I factory reset the phones and the issue was not corrected. I then saw a 7.5.3 update so I tried it on one phone and had the same results. After downgrading back to the supported 7.5.1a everything seems to be working perfectly. I know those two FW releases are new and unsupported, I just wanted to make sure 3CX was aware of the problem for the future.