Can not zoom in online webmap
It's been a while since I did this as I'm now on portal and use dynamic services mostly. But, in Pro 3.2.1 I would create the map I want to make into a tile layer, then choose Publish Web Layer from the Share menu:
Then in the configuration tab, I choose the tile scheme and adjust the slider to include the LOD's that you want:
and I always checked the cache locally button, otherwise I would often get timeout errors:
This will build the tile package in folder specified (C:\temp) and when done, will upload to the organization you are signed into, and build the tiles for you.
R_
This maybe different in your version of Pro (i'm on 3.2.5) so take this for what it's worth.
Sharing a map as a web map will basically make your whole map layer contents into a hosted feature layer, or hosted tile layer, depending on if you choose the configuration for exploratory/editible or the visualization option.
I think if your map layers contain a raster image (e.g. your hillshade) then it doesn't give you the option and instead it will default to creating a Tile Layer.
Although you can drill down and configure some properties of the Tile Layer that it creates, it seems it locks you into using the Tiling Scheme of the current basemap of the map you're publishing from. Maybe that's fine, as long as you get to choose the LOD you need:
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Alternatively sharing certain groups (or individual) layers as a Web Layer means you potentially have more control; you can have different layers that you publish from different ArcGIS Pro maps, to become separate hosted feature layers or hosted tile layers items in AGOL, and then you can choose what you want to add to a web map in AGOL, rather than having them all bundled together. I would generally highly recommend this if you tend to have different versions of web maps or need to republish map layers for various reasons as you're developing a map/app product. You won't be throwing the baby out with the bathwater, so to speak, if you find most of the layers are working the way you intended and only need to modify or republish certain ones.
