Messy bottom layers using a brim - help requested

Hi. This is my first post here. After several months successfully printing with a raft, I am now trying to print with a brim, to minimize waste. I have played with many settings after initially having brim adhesion problems, which I solved by reducing the first-layer height and adjusting temperatures. But now I am having what can only be described as messy buildups of molten filament in certain areas of my bottom layers (top left in photo). Could I please have some opinions as to what I am doing wrong. I am printing on a Diggro (Longer Alpha-3) with PETG at 250 degrees and heated bed at 80 degrees, extruding at 0.1mm. Thanks.
Attachment 14953

your calibratio is way off.

The 'rippled' areas are where the print head is too close to the bed.

If you adjust the z-height/gap upwards in increments of 0.05mm you should be able to hit the sweet spot, where things stick to the bed but can also be removed.

Also manually level the bed.

Looking at the printer - yeah it's basically an ender 3 with a really weird frame.
So help with bed levelling and printing first layer - go look at so,me ender 3 'how'to's.

Thank you for the suggestion - I will give that a try.