I had issues with my BlackVue where there would be huge gaps between recordings. I thought my camera had gone bad, so I researched the issue online on various car forums. Turns out, the problem was with the microSD card and not the camera. Apparently, Sandisk's microSD card design does not play well with the dashcam's constant rewriting on the card. People recommended the Sandisk High Endurance card (not the Sandisk Ultra one) and Lexar microSD cards.
Since then, I've tried out the Lexar and the Sandisk High-Endurance microSD card and found that they don't have the same issue that my older Sandisk did. Right now, I'm using the 128 GB Lexar card.
Bad Card:
Amazon.com: SanDisk 64GB Mobile Ultra MicroSDXC Class 10 Memory Card with SD Adapter - Retail Packaging: Computers & Accessories
Good Card:
Amazon.com: Lexar High-Performance microSDXC 633x 128GB UHS-I, U1 w/USB 3.0 Reader Flash Memory Card - LSDMI128B1NL633R: Computers & Accessories
Sandisk doesn't make a higher 128 GB capacity High-Endurance card (the largest being 64 GB), so I elected to keep my 128 GB Lexar card in for now. So far, I've had no issues with my dashcam recordings.