28.20 issue. No reconnect of sensors and light radar after sleep.

Same here but found that after pausing if you power off and power back on then unpause when you restart ride all sensors reconnect ok . No ride data is lost. 

Tried that today and that worked. Thanks. But I would still like the fix to have it working as before, reconnecting from sleep

I came on here to post a very similar issue!!! My variation is that I pause the ride then lock screen. Cadence and hr sensors are disconnected and won't reconnect until after the ride. This update seems to have created more bugs than it fixed.

Same here. 
This happened to me several times while testing beta 28.xx and today also on version 28.20.

Yes, same problems here. Garmin heart rate monitor and Shimano  power meter P9200 did not reconnect, I did not check the workaround with power off as was afraid loosing the entire ride. Never has such a problem with  Edge 1030..

This is also happening to me every time it sleeps.

Ride; pause; sleep; wake; play = no external ANT sensors

if I pause again; shut down; boot up; play = all sensors are back

searching for the sensors manually does not work 

I can replicate every time. 

This was happening to me on previous builds with edge 1040 solar and this was caused some faulty Connect IQ data field which was causing issues.

If you use any 3rd party connect iq app/field, then to make sure you suffer from the same root cause, I would suggest creating a new profile and not adding any of the 3rd party Connect IQ fields. If this solves your problem, then you may add these fields one by one and this way arrive at the one that causes the problem. 

Now I own 1050 and use quite a few connect iq fields and do not have any issues with device reconnects, maybe my pwoermeter sometimes does not show any data, but that is bit different and easily solvable with on.off toggle on sensor page.