It started when I extended the table from three columns to five columns, in order to add the January 1 baselines. I noticed that the issue was included in michelangelo3's community proposal, so hopefully someone will address it.

Two workarounds are to switch to desktop mode, or in the cell phone Brave browser, it gives an option for "simplified display" or something like that. It's an annoyance, but not enough of annoyance for me to switch back to the 3-column table. ;-)