I'm having the same issue too. It's not EVERY game, but when it starts happening, it happens every game in a row for some reason. I played on launch day, zero lag spikes. Played the day after, had a few lag spikes in primetime (7-9pm eastern), wasnt sure if it was my net, but they stopped so there was no issue.
Last night, had 1-3 5+ second lag spikes EVERY game. I was running a network monitor, no increase in latency, no drop in packets to any of the external sources I can track, completely stable net.
I updated my firmware on my router (though I didn't think that'd help I figured I'd eliminate it), hard power cycled all my equipment, and after about 10pm last night had no more lag spikes.
Come back to play today, starts happening basically every 5-7 minutes and has cost me multiple games. I did have a single game tonight where there was no lag spike, but in every other game I had the issue as described, including it lagging out discord. I even messed with discord to see if there was an issue with it connecting to certain server locations for Discord and it didn't seem to help.
This problem is incredibly frustrating, and I don't have it with any other game. Given that this is a great game and I'd love to play it, I hope this gets a fix. I would assume it has to be a routing issue somewhere (or something of the like), given that many of us are having the exact same problem that suggests it's not just a close-to-home end user issue.
Geographically, I'm in the mid-Atlantic region of the Eastern US (near DC). I assume it's a problem closer to the Apex end, but maybe if we're all clustered in that area it could be a regional thing.