Grass will not spread on to other dirt blocks. They are directly adjacent, plenty of light, and nothing to prevent the grass from spreading.
Almost all my surrounding is dirt now.
I'm playing multiplayer with another player with Windows 10 PC
We migrated the save from a file before the beta
Thank you for your report!
We're actually already tracking this issue at MCPE-41198, so we will resolve and link this ticket as a duplicate.
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