Not quite sure how this is an app issue, as you curate your own feed based on your subscriptions, unless of course your viewing local or all, which then are more instance dependant. Also the way you sort the posts, affects your feed...Have you set a default sort in the settings? or played around with changing the sort options?..

There’s not really an algorithm. All the feed filters in voyager are time and traction based as far as I’m aware. Part of having social media that isn’t primarily designed to influence our thinking in order to buy things or generally encourage you to spend all your time on it means we have to sacrifice having content served up to us based on our viewing habits (I.e. intrusive profile models based on personal data). This means lemmy feeds will sometimes have odd mixes of content because you’re just seeing things in mostly chronological order. Mostly is italicized because there’s some traction based filters but that’s irrespective of the type of content.

Maybe memmy has introduced its own algo? Would be curious if anyone that knows for certain could comment.

Recently I’ve noticed my feed has become almost entirely the main meme instance. The algorithm gives me 4 meme posts then a technology post then load more memes

Yes, same issue, and I'm using lemmy-ui...

Lemmy's backend Top/Active/Hot are pretty primitive. I'm experimenting with some ways to weigh smaller less-popular communities... because +20 vote on meme topics is noise, but +20 on some focused community can be a big deal. hot_rank doesn't take that into account and just looks at published date and score. It's pretty tricky to get new things into the backend, so it may be a while.

Maybe one could try to certain communities from all by there preference to serve as a short term hack.

Voyager goes back to the filter you used last when you open it, others default to "all".