Dahua posted a firmware update for the Color4M-T (IPC-HDW3449H-AS-PV-PRO) rev. 26. I uploaded it to one of my Color4M-T cams, and it worked without any issues; so I installed it on the other two 4M-T’s, and it seems to be working well on all three cameras.
IPC-HDW3449H-AS-PV-PRO
IPC-HDW3449H-AS-PV-PRO