tanent keeps complaining about slow drain

[Ron Singh]

my tanent moved in about 9 months back, in first month they complained about slow draining in bathtub and sinks, however kitchen sink is good.

I paid for plumber that time to check and he did snake in.

house is sfr , ranch, built in 60's, so older plumbing.

now they are complaining again about same, that slow drain in bathroom, and garage sinks.

however toilet and kitchen sink is fine.

wondering what would you suggest, should I send roto rooter or similar plumber to snaje/camera in home or outside ?

there is a huge tree in front yard, roots ? if its root, won't it cause slow drain in whole house ?

who should pay for expenses and what might be the issue ?