For what it's worth, I reproduced (with PS 5.6.27) using MTR queries

...snip...
msandbox@localhost (empty) > SHOW TABLES;
+------------------------------------------------------------------+
| Tables_in_empty                                                  |
+------------------------------------------------------------------+
| XK4P3A_B0ZCUC_4WXPFR_MIDTE7_BOA174_IQJFXC_2AE81C_HP6FVD_1OLDJ0_K |
| _product_instance_new                                            |
| customer_profile                                                 |
| organisation                                                     |
| product_specification                                            |
+------------------------------------------------------------------+
5 rows in set (0.00 sec)

msandbox@localhost (empty) > SYSTEM ls -lha data/empty/;
total 828K
drwx------ 2 marcos.albe percona 4.0K Jul 20 18:54 .
drwx------ 8 marcos.albe percona 4.0K Jul 20 18:54 ..
-rw-rw---- 1 marcos.albe percona 9.9K Jul 20 18:54 customer_profile.frm
-rw-rw---- 1 marcos.albe percona 176K Jul 20 18:54 customer_profile.ibd
-rw-rw---- 1 marcos.albe percona   61 Jul 20 18:54 db.opt
-rw-rw---- 1 marcos.albe percona 9.3K Jul 20 18:54 organisation.frm
-rw-rw---- 1 marcos.albe percona 112K Jul 20 18:54 organisation.ibd
-rw-rw---- 1 marcos.albe percona 9.4K Jul 20 18:54 _product_instance_new.frm
-rw-rw---- 1 marcos.albe percona 192K Jul 20 18:54 _product_instance_new.ibd
-rw-rw---- 1 marcos.albe percona  13K Jul 20 18:54 product_specification.frm
-rw-rw---- 1 marcos.albe percona  96K Jul 20 18:54 product_specification.ibd
-rw-rw---- 1 marcos.albe percona 9.3K Jul 20 18:54 XK4P3A_B0ZCUC_4WXPFR_MIDTE7_BOA174_IQJFXC_2AE81C_HP6FVD_1OLDJ0_K.frm
-rw-rw---- 1 marcos.albe percona 176K Jul 20 18:54 XK4P3A_B0ZCUC_4WXPFR_MIDTE7_BOA174_IQJFXC_2AE81C_HP6FVD_1OLDJ0_K.ibd
RDS: msandbox@localhost (empty) > SELECT * FROM information_schema.innodb_sys_tables WHERE name LIKE '%product_instance%' OR name LIKE '%XK4P3A%';
+----------+------------------------------------------------------------------------+------+--------+-------+-------------+------------+---------------+
| TABLE_ID | NAME                                                                   | FLAG | N_COLS | SPACE | FILE_FORMAT | ROW_FORMAT | ZIP_PAGE_SIZE |
+----------+------------------------------------------------------------------------+------+--------+-------+-------------+------------+---------------+
|      228 | empty/XK4P3A_B0ZCUC_4WXPFR_MIDTE7_BOA174_IQJFXC_2AE81C_HP6FVD_1OLDJ0_K |    1 |     20 |   200 | Antelope    | Compact    |             0 |
|      225 | empty/_product_instance_new                                            |    1 |     21 |   197 | Antelope    | Compact    |             0 |
|      200 | test/_product_instance_new                                             |    1 |     21 |   172 | Antelope    | Compact    |             0 |
+----------+------------------------------------------------------------------------+------+--------+-------+-------------+------------+---------------+
3 rows in set (0.00 sec)

RDS: msandbox@localhost (empty) > RENAME TABLE `_product_instance_new` TO `product_instance`;
ERROR 1050 (42S01): Table './empty/product_instance' already exists
Error (Code 1050): Table './empty/product_instance' already exists
Error (Code 1025): Error on rename of './empty/_product_instance_new' to './empty/product_instance' (errno: -1 - Unknown error -1)