Indian Railway Catering & Tourism Corporation [IRCTC] — regarding retiring room irctc

I booked online irctc retiring room at allahabad railway station for 4-feb-2020.

Issue - most common issue that dormitory most of the time shows "slot not available" on portal so as an alternative i need to book double/single bed room which is expensive than dormitory. It should not be possible all the time that slots are not available because i tried 30 days before also and same message appeared on portal. I tried with both fwd and return journey pnrs with different dates and time but same message appears all the time. I guess there is some issue with irctc website or any wrong intention to force to book single/double bed rooms instead of dormitory. Please look into/ investigate and update on the issue.
If need any other information from my side then do let me know.