To be safe your card needs to be able to write at double that ( 20MB/sec). At 4k Gopro is firing very nearly 10MB/sec at the card.probably more if multiple files are being written simultaneously (. Ps.you could also try using 2.7k rather than 4k. PS my duff card came from PC World! I test every card I buy before using it. If the problem still persists after that, you probably need to take the Gopro back to where you bought it since there is really nothing else you can play with to fix it. If it tests OK I would still try another card to eliminate the card as the cause of the problem. If it is no good, take it back with a printed copy of the report from the software.
Next run a test software to see if the card is a full class 10. So first you could try re formatting the card in Gopro and see if the problem persists. Start every Gopro session with a card formatted in the Gopro. Safest way to manage the card is to use a card reader and merely download ( copy) the files to a laptop/PC drive, then put the card back into the Gopro and format it there. So dont for example delete files from the card with a laptop. Similarly you should not mess with files on a Gopro card other than when it is in the Gopro. If that happens it will corrupt the card because Gopro has its own File Table set up.
The reason being that there is no definitive standard for USB and on some devices ( laptops) a USB port automatically downloads a file to anything connected.
Personally I never connect Gopro to another device via USB. How you manage the card is also important. The vast majority of problems with Gopro is due to the card.either not fast enough or with corrupted sectors. Depending on your settings a separate RAW audio stream is generated.again if the card cannot keep up and given that Gopro has limited buffering, the audio will be lost.