Apple is dealing with a couple of potentially non-trivial issues this week with the just-released Apple Watch.

Potentially the most serious one is with its so-called “taptic” engine, a haptic, or touch feedback, technology that Apple uses on the watch. A key component is "defective," causing production bottlenecks, according to a Wall Street Journal report.

Following the start of mass production in February, testing showed that “some” taptic engines supplied by Shenzhen, China-based AAC Technologies would, “over time,” stop working properly, according to the report.

That caused Apple to scrap some finished watches, the Journal said. This, in turn, is crimping supply of the watch and delaying deliveries. Currently, the Apple Store is showing delivery dates of June in most cases.

During the company’s second-quarter earnings conference call on Monday, Apple CEO Tim Cook said that “demand is greater than supply. And so we’re working hard to remedy that.” Though he didn’t give any reason for the imbalance other than an implied strong demand for the watch.

Research released earlier this week by digital commerce specialist Slice Intelligence indicated that only 22 percent of the 1.7 million Apple Watches ordered by U.S. customers were delivered last weekend.

The good news is taptic engines are also made by a second supplier, Japan’s Nidec Corp., which isn’t having the same kind of production issues, according to the report. Apple is reportedly moving almost all production to Nidec.

Taptic refers to the engine’s ability to “tap” you on the wrist whenever you get an alert or notification or press down on the display. It is also instrumental in sending your heartbeat to other Apple Watch users.

A teardown of the Apple Watch by iFixit shows that the taptic engine is attached to the end of the speaker inside the watch.

The taptic engine uses “subtle audio cues from the specially engineered speaker driver,” according to Apple.

The second Apple Watch glitch purportedly involves tattoos. Long discussion threads on social media sites like Reddit and Twitter point to a potential problem with the ink from sleeve tattoos (which cover the wrist). The ink can interfere with the ability of the watch’s sensor to read your heart rate and get notifications, commenters said.

“The watch would lock up every time the screen went dark and prompted me for my password. I wouldn't receive notifications," said one commenter on Reddit.

“When I decided to try holding it against my hand (my left arm is sleeved and where I wear my watch is tattooed as well)…it worked. My hand isn't tattooed and the Watch stayed unlocked. Once I put it back on the area that is tattooed with black ink the watch would automatically lock again,” the commenter added.

Other commenters, who had similar experiences, seemed to support the claim.

The topic is also trending on Twitter under the hashtag #tattoogate.

Apple enthusiast website iMore.com said that they tested the claim.

“After some brief tests, we're inclined to agree with those early reports — if your tattoo happens to be a solid, darker color,” iMore.com said.

Apple did not respond to request for comment on the taptic engine and tattoo issues.

AAC Technologies has not yet responded to a request for comment on this story.