since you can't do this natively, you've left out some very important info...
namely how are you doing this?
airplay from a phone?
if so, it's probably a wi-fi issue in your house.
if you are doing this, the stream is on your network 3 times.
Spotify --internet--> Router --wifi--> Phone --wifi--> Router --wifi--> HomePod
Try rebooting your wireless & other network gear (routers and such)
or moving the router so you have better signal in the room where the HomePod is (google router positioning)
you could try playing from a computer that's connected via wired ethernet. That would save a couple hops on wifi.
you could try leaving your phone closer to your router. not too close though (about 5 feet away, and to the side (not above/below) works best with most antenna designs)
or if you have 2.4 & 5, make it so that your phone connects to one, and the HomePod the other.
5 is faster, but doesn't go through things well, so once it's gone though a couple walls, you might have no signal left.