@rms911 I noticed the dreaded Buffering... dialog pop up several times last evening while viewing programs on Spectrum app. My connectivity is a Roku TV with a hard wire ethernet cable to the cablemodem, no wifi involved whatsoever. It's in my home office so the TV is less than 6ft from the modem.
And like you, no other apps buffer except Spectrum. Therefore, as I've expressed before on this thread, I conclude that this is a Spectrum issue, Roku dev hasn't responsibility for this.
P.S. Because the buffering was manifesting itself, I decided to watch the MLB All Star Game using OTA, so I wouldn't risk missing some interesting play when the dialog pops up.
don't call me expert, just a long time Roku user that seen a lot of things