Hello. I create tiled galleries on my site also, and here’s the workaround I use. I think it requires the Jetpack plugin to be at version 6.8 or higher.
For a new post:
– Add a Classic Block to the post.
– Click inside the block to get the toolbar to appear just above it.
– Click the Add Media button.
– Click Create Gallery, select your images, then click Create a New Gallery and you should see the familiar options for Gallery Type, etc.
On existing posts that have tiled galleries, the galleries appear in a Classic Block and should be editable like they were with the previous version of the editor. If you convert those blocks to Gutenberg gallery blocks, however, I think you will lose the tiled gallery functions. I’m not converting previous posts, for that reason.
I had thought tiled galleries would be fully supported with the 5.0 rollout and the Gutenberg gallery blocks (either by updates to Jetpack or to the core) but that hasn’t happened yet.
Hope this helps!
Dale