Are you certain that the data has the same sourcetype as you specified in props.conf and transforms.conf? Might you have a typo in one or more of these files? btool is great, but it only checks syntax. btool can't test the actual formatting or regular expressions since it only looks at the configuration files, not the data.
If these hints don't help, please post the relevant stanzas from props.conf and transforms.conf. A little sample data (properly anonymized of course) would also be useful to help the community answer your question.
# based on system access-extractions, but with extra req_duration at the end
REGEX = ^[[nspaces:clientip]]\s++[[nspaces:ident]]\s++[[nspaces:user]]\s++[[sbstring:req_time]]\s++[[access-request]]\s++[[nspaces:status]]\s++[[nspaces:bytes]](?:\s++"(?<referer>[[bc_domain:referer_]]?+[^"]*+)"(?:\s++[[qstring:useragent]](?:\s++[[qstring:cookie]])?+)?+)?\s++"[[float:req_duration]]"[[all:other]]
The search results are not changed however. All looks the same after reloads.