MT4 "Timing Out"

 

I'm having trouble with MT4 kind of malfunctioning after it's been on for a little while. When I first start it up, everything works normally. I can enter trades, drag SL, close a trade, set a TP and so on. After a while, maybe about 1/2 hour, if I try to drag my SL to BE or enter a trade, or set a pending order or close a trade, it just won't work. Price is still moving and showing the current price, I can still use my tools (Crosshair, Trendline, etc) but I can't use the trading functions. Even if price were to hit my SL or TP, the terminal goes from red/green to yellow but the trade doesn't close. I can see that it does close on my phone MT4 app. (All of the functions work fine there), so it is communicating with the broker, just not reflecting what's really happening on the charts. This is happening on my MacBook Pro laptop with MT4 downloaded. I've been using it like this for years with no problem...just recently it's been acting up. If I then shut it down and start it up again, it's fine for a while then the same issue starts again.

Any ideas or suggestions on what might be happening and/or how to fix this?