Hi,
I've had my plant for over a year now but recently started noticing some leaves were browning. When I picked the pot up one of the stems became completely disconnected from it's root ! I saw tiny black bugs around the root and idk if that's the cause or if the soil is just too moist. The other stem in the pot is still connected to it's root and both plants were flourishing. Any advice ? Should the plant be repotted? Do you think I can proprogate the stem with the missing root?

Does the pot have a drain hole? If not, know that adding too much water can make any plant ill in a pot without a drain hole, unless it's a truly aquatic plant.

If that was my plant, I would take it out of the pot, brush away the soil, and see what is going on with the roots. Remove anything that feels mushy, put back in a new pot with new soil. If you see any bugs on the roots, pick them off or rinse them off before putting it back in the new pot.

If nothing is left but the leaf, cut off anything that looks unhealthy and then stick the cut end in water or a new pot of soil. The leaf can grow a whole new plant that way.