I think i had the similar issue as yours whenever it rains for a long period of time which made the humidity skyrocket.

Should be the same as mentioned in below link as well

https://www.reddit.com/r/malaysia/comments/...ugs_on_my_wall/

i tried using a solution which i mix borax and water and wipe of the affected area, the bugs are still there but the amount did reduce a lot. But its not a permanent fix as it did came back if it rains frequently Eg: 10/14 days.

i believe good ventilation also could solve this issue, but i didnt try it as bugs tend to fly into the house as i leave it unintended.