MacBook keeps losing internet, while Wi-Fi is connected (Bluetooth, 5Ghz)
Solution 1:
Looking at your WiFi report, I would say it is not very good overall.
When RSSI reaches 72 the OSX WiFi will try to switch to next best (on your WiFI list).
Yours is at 70 which is not good at all.
Your Tx Rate is also very low (Slow)
Resulting MCS index is to low (2)
Here is an example of excellent WiFi.
Clean (remove) WiFi stations on your list.
Reorder the order of WiFi AP's on your list (drag up or down)
Further improvement to the RSSI can be achieved by switching the Chanel (to avoid overcrowding from other WiFi on same channel.)
You can run this in Terminal that will show last 24 hours of why the WiFi was disconnected.
log show --predicate '(processImagePath contains "kernel") && (eventMessage contains "AirPort: Link Down")' --style syslog --last 1d
Important to know. The AirPort will keep the WiFi information on for some time (making you believe it is connected) before correcting that.