From the document I'm working on now:

- Your sentence may be unclear or hard to follow. Consider rephrasing. (the suggested rephrasing makes no sense and is ungrammatical).

- Add a comma (the suggestion is to add a comma between "the" and "most" in the phrase "the most common")

- Choose a different word (the suggestion is to exchange "heavy" for "cumbersome" when the topic is the weight of steel chain).

- Variety (the suggestion is to swap "hooks" for "angles" when the topic is lifting hooks that attach to steel chains)

Plus, I regularly see crap such as in this image. I've no idea what it thinks it's doing.

https://i.postimg.cc/BvRfnfnP/image.png

Other oddities include Grammarly disagreeing with itself. I apply a suggestion, and then Grammarly flags its own change and suggests I change it back to the original or to something else.

Variety in the context of technical document is wrong by default. You are not supposed to use variety of terms, you are supposed to pick one and stick with it.

Indeed, which prompts me to mention one of the most annoying things about Grammarly. It irritates me no end when I deliver technical writing for a client and they respond with a list of "errors" of that sort after they have run it through Grammarly.