Welcome to the Q&A Forum

OSE seems to be locating your links - up to over 3500 from the other day when I saw was like 300. So I would say when the index refreshes next, you'll see this return. If not, hopefully tech support can help more because it's definitely a weird issue. Headers look fine, robots is ok, no meta robots blocking it & I can crawl with Screaming Frog ... so yeah. No reason other than the glitch that I can see.