I renewed my subscpition to this app recently. When I began using it again, I noticed IF began to lag. Without IF Pax running, and with low power mode enabled, I had no problem. For some reason, with IF Pax running, it lags a little. I closed all the apps that were in the quick launch, I have gigabit internet (450mbps via wifi) on the most recent iPad Pro (larger one).
Hi please take a look at the topic below.
It may be worth going to their own forum and asking there as this will likely be closed for the reasons Jason stated.