When the BBC contacted Petnet on its advertised email address, the email bounced back with a delivery failure notice.
One pet owner tweeted: "My cat starved for over a week", while others complained about other hardware issues.
"My three Gen2 feeders constantly jam and won't dispense food," wrote another.
Some expressed relief that the feeders were now back online.
Petnet has two Twitter accounts. The official one has not tweeted since 30 August 2019 but the support account issued four tweets between 14 and 21 February about the problems experienced.
In its first tweet it said a "system outage" was affecting second generation devices and asked customers not to switch off their feeder even if it appeared to be offline.
It said automatic feeds would "still dispense".
Four days later, it tweeted again to say it hoped to "release more information" soon.
On 21 February it said smartfeeders were "returning online" and a "system reset" was in progress.
Some customers tweeting to the support account complained of not having received a response.
The firm had faced similar problems in 2016.
'Things will fall over'
According to Crunchbase, US-based firm Petnet has received $14.9m (£11.5m) in funding since it was founded in December 2012.
The device is sold for £222 on the Amazon marketplace in the UK.
Nearly 60% of the 554 customer reviews left on the US site have given the device a rating of either one or two stars.
"As we go towards a more automated home you have to acknowledge that, somewhere along the line, things will fall over," said Stuart Miles, founder of the tech site Pocket-Lint.
"Robots and automated systems have hiccups along the way, it's something we need to get used to."