'transform_caps returned caps which are not a real subset of the filter caps' warning in lal_interpolator

Using more recent versions of pygobject (3.28.3) and gstreamer (1.18.x), I'm getting gstreamer warnings when a lal_interpolator element is used:

** (python3:13344): WARNING **: 09:14:07.861: gstlalinterpolator10: transform_caps returned caps which are not a real subset of the filter caps

Adding GST_DEBUG=3, I get a more detailed log message:

0:00:04.857723000 13344 0x55990a4ada80 ERROR basetransform gstbasetransform.c:485:gst_base_transform_transform_caps:<gstlalinterpolator10> transform_caps returned caps audio/x-raw, format=(string)F32LE, rate=(int)[ 1, 2147483647 ], channels=(int)448, layout=(string)interleaved, channel-mask=(bitmask)0x0000000000000000 which are not a real subset of the filter caps audio/x-raw, rate=(int)512, format=(string)F32LE, channels=(int)448, layout=(string)interleaved, channel-mask=(bitmask)0x0000000000000000