If we're looking at simple stats...
Foderingham has played in 3 league games, keeping 1 clean sheet. However, he's faced 9 shots on target and has conceded 3 goals, indicating a save % of 66.7%. Olsen has faced 46 shots on target in 11 games and has conceded 17, his save % is even worse at 63.0%. Both of those save ratios are poor which indicates that our issue is the quality of chance we're giving up rather than the quality of the man between the sticks tasked with keeping them out*.
FWIW, according to fbref.com our goalkeepers have the second worst save ratio in the Championship, only ahead of Luton (which made our 0-0 with them somewhat inevitable!). Verrips has a 20% rate from his only start at West Brom
*to further this argument, Ramsdale has a 66.7% rate from his two starts with us this season and Johnstone has a ratio of 65.7%. Both of those goalkeepers have been deemed good enough to make the England squad this season.
Full table here