Sony PMW EX3 cams 1080p24 but ATEM4K recognize as 1080i59.94

I have 3 Sony PMW EX3 cameras set to 1080p24, SDI cable fed to ATEM 4K they are recognized when ATEM set to 1080i59.94. ATEM doesn't recognize the cameras when set as 1080p24 or 1080p30
Does ATEM 4K supports 1080p24(23.98 hz) or 1080p30(29.97 hz) ?
Do I need to get most recent firmware ?

The setting you are talking about is the recording resolution and framerate (1080P24)
You need to look for settings of your SDI output in the EX3 menu.

Why would you want to run your mixer on 24P? This introduces a lot of problems..
Pan's and fast moves are very choppy.. You won't be able to get a feed from a PC or laptop as they usually don't support 24/25/30 fps..

50/59.94 are the broadcast standards.. Why not follow those?

The EX3 cameras can only output a 720p60 or 1080i50/59.94 Signal, to both meet broadcast requirements, and keep the signal bandwidth within the then SDI standard requirements. Also, most monitors back then only accepted 720p59.94or 1080i50/59.94 also, as 1080i59.94 was the max signal bandwidth the first generation of HD SDI could handle. A 1080p24/25/30 signal requires at least 3G SDI bandwidth.
Cheers

A 1080p24/25/30 signal requires at least 3G SDI bandwidth.

I don't agree with you Denny..
1080i50 is the same ammount of data as 1080P25 An interlaced image is half the video lines of a frame. So 50 half frames is as much as 25 full frames

The SMPTE 292 standard is a nominally 1.5 Gbit/s interface. Two exact bitrates are defined; 1.485 Gbit/s, and 1.485/1.001 Gbit/s. The factor of 1/1.001 is provided to allow SMPTE 292 to support video formats with frame rates of 59.94 Hz, 29.97 Hz, and 23.98 Hz, in order to be upwards compatible with existing NTSC systems. The 1.485 Gbit/s version of the standard supports other frame rates in widespread use, including 60 Hz, 50 Hz, 30 Hz, 25 Hz, and 24 Hz.

The standard also defines nominal bitrates of 3 Gbit/s, for 50/60 frame per second 1080P applications. This version of the interface is not used (and has not been commercially implemented); instead, either a dual-link extension of SMPTE 292M known as SMPTE 372 or a version running twice as fast known as SMPTE 424 is used for e.g. 1080p60 applications.

Ah, senior moment on my part — I stand corrected on SMPTE standard. I was getting HDMI and SDI standards confused. But just the same, the early HD cameras lime the EX3 and AF100did not support 1080p over SDI, only 720p or 1080i to conform to broadcast standards. Yes 1080p24/25 should be the same data rate as 1080i50/60.
Thanks Daniel for the correction.
Cheers