rpivottable分组类别旁下拉列表点击后打开位置异常问题

点击rpivottable分组类别旁的下拉箭头时，对应的列表会在页面顶部打开，最初我甚至以为该功能完全失效。正确的展示位置应为箭头旁，如下图所示。

可复现问题的rmarkdown示例 #

---
title: "rpivottable_test"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)

R Markdown #

r stringi::stri_rand_lipsum(10)

library(rpivotTable)
data(mtcars)

包含可视化内容 #

你也可以嵌入可视化图表，示例如下：

rpivotTable(mtcars,rows="gear", cols=c("cyl","carb"),width="100%", height="400px")

![示例图片](https://i.sstatic.net/UcwPU.png)

### 运行环境信息
```r
> sessionInfo()
R version 4.1.2 (2021-11-01)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19043)

Matrix products: default

locale:
[1] LC_COLLATE=Greek_Greece.1253 
[2] LC_CTYPE=Greek_Greece.1253   
[3] LC_MONETARY=Greek_Greece.1253
[4] LC_NUMERIC=C                 
[5] LC_TIME=Greek_Greece.1253    

attached base packages:
[1] stats     graphics  grDevices utils    
[5] datasets  methods   base     

other attached packages:
[1] rpivotTable_0.3.0

loaded via a namespace (and not attached):
[1] htmlwidgets_1.5.4 compiler_4.1.2   
[3] fastmap_1.1.0     htmltools_0.5.2  
[5] tools_4.1.2       knitr_1.36       
[7] digest_0.6.28     xfun_0.27        
[9] rlang_0.4.12 

内容的提问来源于stack exchange，提问作者Yorgos