Compost ruining drainage - normal behavior?

Hello. I've noticed that when I use compost in my mix, my soil behaves completely different than if I don't use it - and not in a good way. Without compost added, I can water a pot as much as I want in a single watering session and the drainage stays consistently good. When compost is added, the drainage gets worse the more I water until eventually the water starts puddling up and draining very slowly.

Yes that’s why we add some perlite and coco coir to lighten the mix and improve drainage. Also sounds like you are using a crappy base soil; try to find something better if you can.

Get a better texture compost or, even better, EWC.
Or don't exceed 12-15% total mix volume if your compost is very muddy/heavy.

You can also add aeration.

Rice hulls,pumice,sand/greensand/minerals. Castings/compost/vermicompost are all going to hold more water than peat. Peat by itself drains super well because it's actually extremely hydrophobic when dry so you kinda really have to soak it to get it to fully saturate. Compost tends to absorb more water as it flows through but it's easier to pack tighter than peat so you need more aeration and things in your soil that help stop compaction. Also having a small cover crop helps with drainage a bit as well, just having roots in your top soil layer helps give the water a better path down into the soil and will help you use less water to saturate your container while also stopping some of the evaporation. If you don't want to use cover crop use a mulch to keep the top layer of soil moist and things usually go smoother.