For those saying they're having WiFi disconnect or WiFi problems, just saying "I too have 3004.388.6_2 WiFi issues" isn't enough information. It would likely help RMerlin/others assist in the diagnosis if you posted as much information as you can about your WiFi and router setup. Information like:
What is your WiFi configuration
Does the issue happen on a specific WiFi band or on both bands
Does the issue happen when using Guest Network WiFi, if so which Guest Network WiFi are you using
What was WiFi channel before WiFi issues, and what is the WiFi channel after the issue started
Does the system log show any issues around the time the WiFi issue(s) happen
Are you using AiMesh, if so what is the mesh setup (router model and firmware version on the nodes)
Is the issue with devices connected to the main router or a AiMesh node WiFi
Does the issue happen with all WiFi devices or only certain one (if certain ones which ones specifically)
Are you running any add-on scripts, if so which ones
What other features/options are enabled on the router (AiProtection, QoS, USB, etc.)
And so on.
More information is needed to help the group diagnose these issues and find a common cause since some running the 3004.388.6_2 firmware are not having WiFi issues.