What can I do if I think someone is downvoting all of my posts?

I banned someone from a community I made for breaking a rule and being excessively rude, then they DM'd me and after a report their account got banned and I think that they might've made an alternative account and have been downvoting/disliking all of my posts. What can I do to stop/fix this, is there a way for me to see activity on my community as a moderator? Sorry if this doesn't fit here, I don't really know where else to ask this question. It's a small community so any post I make will get buried when the moment I make the post it gets downvoted.

I haven't ruled out that this could just be coincidence but if I can do something about it I'd rather know.

Edit: Maybe a feature request to consider in the future is allowing the user to see activity on their posts, that way if they do notice a trend they can deal with it personally (ie block the user responsible). It's a feature available on other social platforms and seeing as Lemmy logs that stuff anyways. I dunno it just seems like a nice to have. Food for thought I guess.