Running Dynamics

That is normal. To get these data, you need additional sensors, like a footpod or a HRM Pro chest strap.

ovekvam said:

you need additional sensors, like a footpod

A foot pod does not provide running dynamics (except cadence). Sensors that provide full set of running dynamics are the RD pod, HRM-Run, HRM-Tri, and HRM-Pro.

Anyway, latest firmware provides wrist-based running dynamics, without the need for additional sensor, so make sure you have the latest firmware.

I think some footpods, like the Stryd, provides running dynamics. 
And it is not so easy to get the latest firmware currently, since Garmin seems to have blocked all firmware updates for the FR255 lately. And is the wrist-based running dynamics complete? I think it is still missing some of the data. 

ovekvam said:

I think some footpods, like the Stryd, provides running dynamics.

But this data do not conform to the ANT+ RD profile, which means that it will show only as 3rd party IQ data, and won't be incorporated into any running dynamics related summaries in garmin connect.

ovekvam said:

And is the wrist-based running dynamics complete? I think it is still missing some of the data. 

Indeed, it does not have ground contact time balance.

Tank you. 13.23 firmware and no wrist-based running dynamics. It's seems to me I have a problem with watch.

Once Garmin sorts out updates for the FR255, you will get wrist based running dynamics. Your watch is probably just fine.

For those saying you need a footpod, that is incorrect. I don't have a foodpod and my 255s gives me all those dynamics. 

Forerunner 255 Series Software Update 15.19

Change Log: Adds support for wrist-based running dynamics.

So you get ground contact time logged without external sensors like a heart rate strap?