Replacement secondhand RT AC88u proving problematic

[jak8]

After almost 10 years of using an AC68U I have in the past 2 weeks obtain a relatively new 2020 AC88U and after a factory reset continued to load up the latest merlin as I have used this excellent firmware since forever with absolutely no problems until now with the AC88U which is proving impossible to load any certificates on. After innumerable failures I started to look at the logs in detail and found I was getting logs where the dates were discontinuous and included records for dates a month before I actually acquired the router and certainly prior to the factory reset.

I have obviously no knowledge of its previous life but feel I ned to undertake asomething more than simply a factory reset to address the problems I am experiencing.

Seeking advice on how best to make sure Nvram and Jiffs are thoroughly cleaned.

 

[Deleted member 22229]

Format the JFFS partition on next boot option on admin page dont forget to hit apply after selecting that option then reboot.

 

[jak8]

OK so after 4 days shut down whilst away I rebooted the AC88U and then once stable checked to wipe the Jiffs which was at approx 4MB and also cleared out the syslog which I view as corrupt in that the entry dates ran from Aug10 - May 5 followed by Aug 11 entries and then Aug 18 following the reboot.
Checked Syslog again and found it remained as earleir ie still corrupted. Repeated the process 3 times and progressively got the syslog date to clear up to an extent where the dates commence at May 5 and progress in order but still fail to understand why there are logs from months before I even acquired the router! Furthermore the Jiffs remains at 2MB even after having supposedly being wiped 4 tims in the past 2 hours.
I intend to do a full factory reset but wonder if a simple factory reset via the GUI will suffice to correct what I, possibly being a NOOB , consider the results of these attempts to format the Jiffsand 'syslog' clearing indicate something more is required?

While attempting this Jiffs formatting and clearance of Syslog an USB loaded with Diversions etc has been plugged into the 2 port.

Advice appreciated