When you download orbit files, it’s not for a specific acquisition but for a specific date. You have one orbit files for each day for each satellite (i.e. 2 orbits files per day).
If you want precise orbits for one day, you can simply download it from there https://qc.sentinel1.eo.esa.int/aux_poeorb/ and put it in the directory you mentioned. Note that that’s what SNAP is supposed to do. Maybe a firewall or something is blocking SNAP ? I’m not an expert in these things though.
If you still want to manually use precise orbits, you probably know that precise orbits are only available after a time lag of about 2 weeks.
If the last orbit file available, i.e. this one : S1B_OPER_AUX_POEORB_OPOD_20190218T110752_V20190128T225942_20190130T005942
These orbits are not related to the 18th February 2019 but from 28th to 30th January 2019, as you can read from the filename.