Major INDI Library release v1.9.0 bring significant internal changes championed by @pawel-soja to modernize core INDI Library drivers and clients. New drivers for DeepSkyDad Flat Panel & Pegasus devices plus further improvements to PCM8 drivers.
Check that iOptron is connected in INDI. Select telescope in your equipment profile. You have to set at least the primary telescope. Right now it appears no telescope is selected and you see a warning about missing focal length.