Verify height issues

While laying out some flight plans for photogrammetry in difficult terrain, thought I’d use the verify height function. Odd thing, I enter for example a relative altitude of 100m and the waypoints reflect the adjusted altitudes. But when checking in map tools with the Elevation Graph function, it shows my above GE and SRTM ALT around 30m. Weird. Does the verify height just ignore my 100m and go with 30 lol? When laying out grids for software like pix4d, going higher only messes with you GSD. Flying lower makes the entire scan useless as you lose you overlaps.