Rmarkdown unable to display some output inline

When running code chunk whose output is a tibble format or a data.frame, the result cannot be displayed inline even "chunk output inline" is enabled.

for code like
test = data.frame(x = c(1,2), y = c("?", "a"))
test

The data.frame is created normally but cannot be displayed inline.

I have tried to update Rstudio and rmarkdown to latest version but the problem persists. If I use the "chunk output in console", the result can be displayed in the console.

Hi @ruser2019

If you have an Rmd file as shown below and run the df-chunk only, does the table show up in the document?

---
output: html_document
---

```{r df-chunk}
iris
```

@mattwarkentin no, nothing showed up

What version of RStudio are you using? You can check this by running:

RStudio.Version()$version

RStudio.Version()$version
[1] ‘1.2.5025’

if you need any diagnostic report, let me know how to generate it. thank you for the help!