PCB review interference

I've designed a prototype PCB for a data collection product. It's a 150x100 cm board with less than 30 components on. On top of the board I have a RPI 3 model B connected with a 40 pin cable. The board has connectors for USB, LAN, power and a 433 MHz receiver circuit. In all pretty simple. Files are in DipTrace format. After a few iterations (probably when adding a ground plane to improve/secure 433 Mhz reception) I got interference on the USB port. (Connected with a short USB-cable to the RPI with ferrite-beads on data-lines). The interference was discovered on printed board. We use a USB-dongle-modem (noisy I think) and after a while when sending data it cuts the line and the modem restarts. I'm not a professional in PCB layout but have simple equipment like multi-meter and a low end scope to perform tests if needed. What I need help with is two parts: 1. Overall review of board design (especially PCB layout design). Suggestions and gotchas of what can be made better in terms of stability. And most important 2: What should I change to make sure the USB-interference is eliminated. I'd like to work like this: * Agree on project forms based on discussion and simpler images * I'll send over diptrace-files * You review * I do measurements and make tests if needed * I'll redesign the board * You review again (this might need to be iterated a few times) * Done If things go well, I'll probably have more work when moving forward with the board. Regards, Jens