Thanks for your question. I talked with our tech team and this is a known issue.
This is since version 28 of the Rockwell software. All network packages are divided into small packages, which means that more messages have to be sent and therefore it takes longer to wait. Known issue. Rockwell is working on a solution.
Use FactoryTalk Linx to set up the connection to the PLC. While this is not a full solution, it does improve the connection to some degree when compared to using RSLinx.
Wait for Rockwell to fix the issue. This is a known issue and Rockwell is working to resolve it. They aim to resolve it in the next version (version 33) and aim to release it by the end of the year. As with all things development, they cant give any guarantees.
Invest in a “solution” right away by placing a “Box PC” on location and remotely controlling that Box PC via VNC. Since the communication between the Box PC and the PLC is local, downloading etc is much faster. However, this is a very pricey solution, as the price of the Box PC is roughly 2x that of the IXrouter, depending on which variant you’re using. This is of course no ideal solution, but it is a work-around. It is then your choice whether this option would be worth it for you. If you’re interested, please contact your Rockwell distributor, they may be able to provide you a Box PC.
My advice is to first try using FactoryTalk Linx. If you are already using that, or if you still find it too slow, you can either choose to wait or to invest in the pricey Box PC “solution” right away.
Rockwell is working on a solution in the next software version (33) which they aim to release by the end of 2020.
Hope this helps!