Thank you, Craig, for your valuable input. Based on that, we carried out the following checks:
We checked the READINGTYPE behavior on both a standard Maximo VM and our KDD instance where the Transport add-on is installed. On the VM without the PLUST add-on, the field is editable. However, once PLUST is installed, the ASSETMETER class changes from psdi to plust, where the field is only editable if METERTYPE = CONTINUOUS and only for new rows.
This explains why READINGTYPE is not editable in our case. However, making it read-only is not justifiable, as it leaves us locked in a situation where we cannot adjust or correct the field when required, creating both operational and maintenance challenges.
I would appreciate your guidance or support in finding a way to address this limitation.