Yes, inceasing icon size solve selection issue. Kinds of annoying though that I can't keep them as small as I would like to.
When adjusting icon size in portal fence I can't tell when is it exactly same as in normal fences. Tried multiple variations, neither made both fences snap same way.
If I untick "Keep Fences sized to even multiples of icons" there is no snapping and I can adjust size of fences to be roughly equal. However I will proably will keep this enabled to have snapping as adjusting size without that is kind of inconvenient.
Rebooting doesn't change anything.
Temporarily untoggling snapping and adjusting fence size is ok workaround, but I would still consider this case of poor usabilty that deserves to be fixed / improved.