I have a 2017 MBP that at times is very slow on wifi, this happens when bluetooth is on. On the same wifi network my 11 yr old iMac runs fine. Has anyone heard of internet problems with the 13" MBP?
Yes, very common. Since 2016. Welcome to yesteryear
The problem arises when you use 2.4 GHz Wi-Fi instead of 5 GHz. Both Bluetooth and 802.11bgn use very similar 2.4 GHz bands for communication and can therefore interfere with each other. The only solution is to either disable one of them or to switch your Wi-Fi network over to the 5 GHz band.