@breinbaasnl Could you confirm where this code is running?
If it’s using the uplink (which it seems to be from the logged output)
then the fix to the bug on this thread hasn’t yet made its way to the anvil-uplink package.
You’re right about the fix you’ve implemented.
Anvil has, for a long time, converted numpy floats to python floats before serializing them to the client, so that you didn’t have to.
The original code that did this used the (now deprecated) asscalar method.
We fixed that on Anvil’s own server code, but the fix hasn’t yet propagated to the anvil-uplink package.
I’ll flag that we need to push a new release of anvil-uplink.