The answer to 'why is my drain trap slow draining' is that the drain trap is likely clogged with debris, hair, or other buildup. A slow-draining drain trap is a common plumbing issue that can be caused by a blockage in the U-shaped pipe under the sink or tub. This traps water and prevents the drain from flowing freely.
Some common symptoms of a clogged drain trap include gurgling sounds, water draining slowly, or standing water in the sink or tub. Fortunately, this is usually a simple DIY fix that homeowners can address themselves. However, if the clog is severe or difficult to remove, it's best to call a professional plumber to inspect and clear the drain trap properly.