Rough transition from Mitsubishi A- to L-series

For nearly 20 years, my employer (an OEM) used the A1SJH in a portable testing machine that required calibration of several sensors. The calibration data was stored in volatile memory, along with settings for the test. From time to time, I upgraded the control software in older machines, and this never affected the stored calibration data and only once had a minor effect on one test setting. We transitioned to the L-series (L02CPU-P) shortly before our software engineer retired. I have found that upgrading the software on the L-series also wipes out the calibration data. While this information is fairly easy to reload, I'm wondering if there is a different memory location where this type of data should be stored. The control software has the same "look" as it did with the A-series, a handful of files called main, parameters, etc. It seems the calibration data and settings are packed in these now. I'm not a programmer- I operate the help desk for our customers and lack the specialized skill we lost when my pal retired. Any ideas to fix this issue would be appreciated.

In all Mitsubishi PLC's the data is stored in the "M", "D", "R" bits, some of these are retentive but the areas can be changed, this change is done in the parameters so you can make an area retentive. See pic.
What you should do is upload from the old PLC the memory area (usually called MAIN), and the PLC Parameters, this will store a snapshot of all memory internal bits/words into the original "A" series file, this also applies to the PLC parameters just in case this has not been updated. It will depend if the retentive area was set in the PLC in the parameters, on a "A" series I believe it is not set by default.
As it has already been converted you may have to put in the data & then upload a copy to your project so you have a snapshot if you loose battery or have to change the PLC, I would definitely check the "LATCH" area in the PLC Parameters & ensure it covers any retentive words you require, this is assuming you are using "D" memory.
It is possible that the latch area has not been set but if in doubt then set the maximum you can in the parameters file, this will ensure the data already held in the memory is "LATCHED" should the PLC go into stop or power down, loss of battery will lose the data however, so you really need to update the Main data from the PLC just in case.

Just to be clear it is possible when you converted the file it did not contain the data in the "MAIN" copy of the data (people often forget to take a snapshot), so this should be done from the original processor to the original file before converting. Then all the files downloaded to the new processor, again check the "LATCH" area in parameters are the same after conversion.