Ripgrep seems to return WAY LESS results than GNU grep

[RVFET]

Workdir:

.
├── MEGAFILE01.txt
├── MEGAFILE02.txt
├── MEGAFILE03.txt
├── MEGAFILE04.txt
├── MEGAFILE05.txt
├── MEGAFILE06.txt
├── MEGAFILE07.txt
├── MEGAFILE08.txt
├── MEGAFILE09.txt
├── MEGAFILE10.txt
└── MEGAFILE11.txt

ripgrep command:

rg -oNI ".*SEARCHREGEX.*"

Result count: 29

grep command:

grep -r -s -i -a -E --include "*" "SEARCHREGEX"

Result count: 85

Due to sensitivity of the data, I'm unable to show neither the original search regex, nor the results returned. For both commands SEARCHREGEX is a "domain.tld" (eg: google.com).

[BurntSushi]

Well without an MRE I can't give you a concrete answer. But I mean, your commands aren't even close to the same, so I'm not sure why you would expect them to produce the same result.