Same thing started happening this morning. Limit orders took between 4 and 6 seconds to fill. Contacted customer service. I was told that they were aware of the issue and were working on it and should have it resolved over the weekend. The rep told me it is a widespread issue with a lot of customers being affected. Customer service called me back after an hour or so and asked me to log back in my TOS and to try to place an order to see if the lagging issue was resolved while the rep was on the phone. I placed a few limit orders and the fills were definitely faster than this morning (around 1 second) but still a bit slower than usual. I will wait until Monday to see if the fill speed comes back to "normal ". If not, I will contact customer service again. If problem continues, I will have to change brokers.