I recently encountered this issue with no previous changes on my end to network or anything else.
I've tried every combination from re-linking, rebooting, joining the Google Home preview program, turning off device controls, other family Spotify accounts, etc.
Since I've made no changes prior to this issue spontaneously happening and I've tested any reasonable solution that I can do from my end, I'm inclined to think it is an issue between Google and Spotify.
If it persists for more than a month I'm going to have to switch everyone to Google Play Music...
My daughters got me Spotify for my birthday and I linked it to my Google Home device and immediately had this problem. I'd been listening to the free Google Music service ever since getting my Google Home device post-Christmas. I hever had a problem with the Google Music service, but the problem started immediately with Spotify.
I've tried unlinking and relinking and after that two songs might play without any buffering but by the third song I get short buffering gaps, and by the fourth song the hiccups get to be ten to fifteen seconds long and it only gets worse from there.
Basically Spotify with Google Home is unusable. Given the number of users who have this problem this should be fairly easy to solve.
I have excellent Internet service, high download speeds and low latency, top-quality routers - I work in IT - and a well-designed home network. Plenty of devices work without fail.
My best guess is that whichever server Google Home uses in my local area has a lousy link to Spotify so it's a problem that varies based on one's location. I live in a suburb of Toronto, a reasonably decently-sized metropolitan area, if that helps.
I'm on Rogers. After doing a little more digging, I think my router, particularly the 5G band, is exacerbating things. Try another frequency on the router/phone, and failing that, switch out the router.
I'm also on Rogers, but I don't use the Rogers router for this wifi. I have another high-end Asus AC router to service the location where my Google Home is located. I typically use the 2.4GHz band and this router is set for channel 11 which is lightly used otherwise.
I'll try switching Google Home to use the Rogers router on its 2.4GHz band which I've set to channel 1. Logically I can't see how it would make much difference, plus the Rogers router is a Hitron device that requires me to reboot it every now and then when it gets hung up. I never have to do that with my Asus routers.
I'm still betting on the regional Google service not playing nice with Spotify. That's probably why linking and unlinking work for some people. They establish a connection with a better regional server. Doesn't work for me though.
mfraser just like you I am on Rogers and also have a high end asus router (rt-3100) as my main networking device.
A lot of coincidences there.... LOL
I am not sure if I can manually assign devices to the 2.4ghz band on my asus router...I think they auto-select. Unless I disable my 5ghz band which is not really an acceptable solution to me....and again I just don't see how it can possibly affect anything, unless Google's own code somehow makes a differentiation between 2.4ghz and 5ghz networks in how it handles streams.
I should mention that Google's official answer is to immediately submit feedback from the Home app after encountering this problem with the keywords Spotify Cutting/Skipping (I think those were the words) for them to review. As if they are fixing this on a case-by-case basis because of a provider network problem.