As recommended in the ACI 435R95 report (section 4.3.3),CSI Software has reduced the default modulus-of-rupture value from 7.5√f 'c to 4√f 'c. This change has been documented as Incident # 19168 in the CSI Release Notes.
Through manual overwrite, users are welcome to comply with the previous 7.5√f 'c value, or apply another value based on engineering judgment or project requirements. This is done by selecting Run > Cracking Analysis > Cracking Modulus of Rupture > User Specified, shown in Figure 1: