"Contents contain" conditions now failing

Hazel has worked well for years. I use Hazel primarily to inspect the contents of generated and downloaded PDF financial statements, to rename the files to a consistent format, and to place the renamed files in the appropriate folder.
Recently, however, most of my rules have stopped working. On closer inspection, using the Preview feature, I've discovered that any "Contents contain" condition, that has worked flawlessly for years, is now failing. If I change the condition to "Contents contain match", with the exact same pattern, the condition matches.
What once operated seamlessly in the background now requires constant attention as I discover files are not where they are expected to be. I need to locate the original file, then load up Hazel and find the applicable rule, run the Preview to see which conditions are now failing, and then individually fix each failing condition. I've got probably a hundred rules.
Recently, however, most of my rules have stopped working. On closer inspection, using the Preview feature, I've discovered that any "Contents contain" condition, that has worked flawlessly for years, is now failing. If I change the condition to "Contents contain match", with the exact same pattern, the condition matches.
What once operated seamlessly in the background now requires constant attention as I discover files are not where they are expected to be. I need to locate the original file, then load up Hazel and find the applicable rule, run the Preview to see which conditions are now failing, and then individually fix each failing condition. I've got probably a hundred rules.