after today maps update 2019.20 the reboot and map loading takes very long time?

Well let's see, I don't think I have anything that would matter in this case.

Also the battery usage after those map updates took long was much higher than normally, something like 15% when normally 3%.

No watch faces, and CIQ apps that might not be factory default are:
Strava Routes, Strava Relative Effort.

And then CIQ that I've installed Running Power, Combo Running Power and Barcode Wallet.

So I would say that the problem is totally with the map files, also when I removed the all map files, the boot-up time was fast as there were no maps.

Well, everything does work, but, "Around Me" takes 2-1/2 to 3 minutes to display now as it used to be mere seconds before the map update. Still running the beta software.

It's seconds for me, so I would guess that also your boot up time is affected.

I would try doing what I did to fix it:

- Move all *.gma *.img files to your computer (for backup to restore if things go bad)
- Reboot the watch with 15s for the power button (it's quick)
- Connect to Garmin Express and re-install all maps
- Disconnect, hard reset 15s for the power button. This took couple of minutes with loader bars for maps.
- Connect to Garmin Express to check is there timezone update or it installs it (might do it also in first stage can't remember)
- Next normal power off should be normal and around me also.

But of course, YMMV, but this is how I did fix my slow map loading. Plain reinstall just made it even worse for me.

I have v2.80 so it's not because the beta.

I have done this a couple times now. The second time after I disabled in Windows 10 the already downloaded map files so they would be a fresh copy downloaded from Garmin, not a cached copy.

Everything works. The map loading is fine, but it still takes many minutes to see the "Around Me" screen.

I was looking thru the Menu>System>About screens and found something that may be of value...

Just after this screen

I see this

Am I missing a file or have a corrupt one which otherwise I would have some other screen data shown instead of None...

How did you update the map?

With garmin express 

i know, that this could solve the prob, but then you have to install it 2 times, 2 time arround 1 hour for installing, seems there gone something wrong with the update, anyway, there was no other way, i installed it a second time and now it is OK!

I had this problem after the 3.30 update along with really sluggish operation. It was literally taking around 20 minutes to load the maps. Two map re-installs and hard-reset later and all is back to normal.

Same on my Marq Expedition - nearly all fine agai. Just 'around me' does take several minutes ..