Slow upload speeds could be due to your home internet if on WIFI.

For example, at SlatableHQ our Spectrum cable upload is only 10Mbps, whereas AT&T on 5G in our area is 40Mbps.

You can google Internet Speed Test to see what your speeds are.

If the upload speed is an issue, we suggest turning off WIFI, as long as you have good reception, and also make sure you're not going to be charged for data usage as files can get large!