Strange Nether Portal Flickering

     This persistent flickering has begun to plague my game regardless of whether I am playing single-player or multiplayer (even worse).  The flickering primarily effects certain blocks and mobs/players. I've tried removing all my mods, resource packs, and reinstalling Minecraft as a whole, but to no avail. I've also tried playing on different versions, but the flickering persists. In addition to the flashing that those entities experience, the whole screen flickers a purple shade and I am able to make out what looks to be a nether portal animation. I would greatly appreciate any help in solving this issue as I find it unbearable to stare at the screen in this state. 

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     Update: 6/4/20

     Hello again, I've finally gotten around to responding to this issue as I was fairly preoccupied before. Since last time, I've changed out the Vega 64 for a 5700XT and while characters and mobs no longer flicker, the nether portal flickering persists. This is as of the most recent release of Minecraft so I'd appreciate any help in solving this issue.