Paper lasts 2/3 years from date of manufacture including time spent on store shelf. Get flat fog after that. Long story I do not wish to explain. 7 was correct years ago, many years ago.
Working strength developer lasts 6 to 8 hours even if you bottle it up after one print and use it the next day. Low contrast flat prints.
Print in total darkness is the most easy way to check safelight. Better ways exist.
I can not see you neg and if it has enough contrast. Develop longer is cure.
If you are working from a half full bottle of stock developer, it probably went bad. I decant stock to small bottles when first opening or making.