When typing a misspelled word, macOS highlights it with a red underline. When right-clicking that word, macOS suggests alternative spellings. This works across all apps, but is broken in the latest Aeon Timeline 3 (3.0.7). No contextual menu pops when right-clicking a misspelled word in an Event text field. I’ve only checked Event text fields, so unsure if it is broken in other areas. The workaround I’ve found is to copy the word, paste it into another application, correct the spelling with the contextual menu there, then copy/paste it back into Aeon Timeline 3.
MacBook Pro (16-inch, 2019)
2.4 GHz 8-Core Intel Core i9
16 GB 2667 MHz DDR4
AMD Radeon Pro 5500M 8 GB
macOS 11.6