Welcome to BF.
If as you say that you've ridden that saddle on the same bike for years, and not had chafing, then you should look to what changed...
Of course, 'aging' brings on new unexpected issues, so there might be that...
Otherwise look to things which have changed.
If your 'fitting' came with a change in saddle height/position/tilt or any combination of that, review that.
Body tilt, due to a position change will also affect that.
Washing & Detergent and any other things used, such as softener - has that changed ? If the shorts aren't getting fully rinsed after washing, any residue will enhance the chance of irritation.
The brands you mention are also those I have and have used for many years, they have always been good quality, fit, well fitting and never have had issues with them - but that's me, and our entire club of 200+ riders.
In the past 35 years of regular riding I have never used any kind of cream - Chamois cream or any other....
Back in the day of real chamois, I and many others, used cream to soften the chamois leather after washing, otherwise no other ointments down there. Creams and ointments can block the pores, which would cause boils and similar conditions.
Keep that area clean as possible. I wash the shorts after 50+ miles of riding, or max 2 rides (if the first ride is easy and not a lot of perspiring).
I the summer, after every ride. I have a doz+ bottoms (shorts/bibs) which get rotated for rides.
Some are heavier for cold weather, some are very light for very warm rides, and then there's everything in between, etc.

The Newest center cutout saddle designs have large/wide cutout channels and would seem to be the best to relieve any pressure in that area... Maybe try one of those.
I have saddles with channels and more old school designslike the Sella Italia Strada, and many others of different shapes - my only hard and fast criteria for a saddle is a good skirt cutout/contour and 143 ish width at the sitzbones - no less and not much more...

Once you have chafing, it tends to persist, if you don;t give the area time to heal. That doesn't mean no riding, just adjusting position or riding type to take away any real chance for it to continue. It also means reducing saddle/riding time length.
Good luck in finding resolution
Ride On
Yuri
EDIT: just saw your reply to others, above. You don't mention how large/big you are (weight/mass). Maybe the saddle is worn out?
Again, any changes in position will have a great affect on this.
I also use Cera Ve daily, but only after a ride/shower. Great stuff for the skin!
...maybe an underlayer (wicking underwear) with legs, used short term, might stop chafing long enough for the skin to heal ?