Trying to Calculate SLA on Network days

I am trying to Calculate SLA on resolution times.

Column H - Date/Time Logged - 2022-01-03 07:42:42
Column I - Date Resolved (sometimes blank) - 2022-01-04 09:00:32
Column J - Current Date - 2022/01/20 0:00 (would prefer to have this set to 8am on the current date

I have tried creating this formula
=IF(ISBLANK(I3),NETWORKDAYS(H3,J3,'Network days'!B510:B523),NETWORKDAYS(H3,I3,'Network days'!B510:B523)) - this was SUPPOSED to calculate the SLA based on if Data resolved is blank and if it is then calculate against today's date.
I receive a #value! error
Business hours are 8am - 2pm, no weeekends & no stats are included.

I'm not new to excel but only familiar with basics, some formulas. I have been doing some research and just can't finalize this. I'm in a new role that will require specific SLA calculations, really would appreciate some assistance. I have the spreadsheet I am using and can share if necessary.

Thank you in advance.