Long-lasting plateau in SBS1108+574

Using ATLAS forced photometry (Tonry et al. 2018; Shingles et al. 2021), I noticed this EI Psc-type object showed long-lasting during some of its superoutbursts. The shape of these superoutbursts somewhat looks like those of standstill-like phase of superoutbursts in some AM CVn-type outbursts (EI Psc stars are between hydrogen-rich and AM CVn stars and this is natural).

The unusual behavior in MASTER OT J055845.55+391533.4 may be similarly explained.