I think I remember you saying that you have a Pico.. so yup, not an issue.
Most modern mods (last 2-3 years) have passthrough and can charge batteries just fine but many are still stuck in the dark ages and believe the old tales of mods not charging batteries correctly.
Some models of mods may have quality issues and have several issues, so you should always look reviews and information about your mod just to be sure, but I've yet to see any bad stories about bad charging with mods in a very long time. Lots and lots of people ranting about it, but actual issues, not so much. I usually see mentions of some mods being overall bad ones, mostly 510 pins failing, crappy/cheap internal wiring, buttons not working any more, screens going black, people doing bad things (like dropping it several times) and blaming the mod. But charging issues, nope..