Toilet temperamental

[tpf903]

I have an old low gallonage toilet. It flushes fine when when liquid waste is present.
Every time, when there solid waste in the bowl (not a lot) it clogs.
I need to use a plunger each time to get the waste to flush.
I made sure all the holes under the rim are clear.

 

[SimonG]

Something stuck in the pan connector or soil pipe. Those stupid plastic toilet cleaners can cause this.